do not use call integration on devices w/o telephony support

src/main/java/eu/siacs/conversations/services/CallIntegration.java

@@ -1,6 +1,7 @@
 package eu.siacs.conversations.services;
 
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.media.AudioManager;
 import android.media.ToneGenerator;
 import android.net.Uri;
@@ -50,7 +51,12 @@ public class CallIntegration extends Connection {
     public CallIntegration(final Context context) {
         this.context = context.getApplicationContext();
         if (selfManaged()) {
-            setConnectionProperties(Connection.PROPERTY_SELF_MANAGED);
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                setConnectionProperties(Connection.PROPERTY_SELF_MANAGED);
+            } else {
+                throw new AssertionError(
+                        "Trying to set connection properties on unsupported version");
+            }
             this.appRTCAudioManager = null;
         } else {
             this.appRTCAudioManager = new AppRTCAudioManager(context);
@@ -151,7 +157,11 @@ public class CallIntegration extends Connection {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
             setAudioDeviceUpsideDownCake(audioDevice);
         } else if (selfManaged()) {
-            setAudioDeviceOreo(audioDevice);
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                setAudioDeviceOreo(audioDevice);
+            } else {
+                throw new AssertionError("Trying to set audio devices on unsupported version");
+            }
         } else {
             setAudioDeviceFallback(audioDevice);
         }
@@ -309,7 +319,7 @@ public class CallIntegration extends Connection {
     @Override
     public void onStateChanged(final int state) {
         Log.d(Config.LOGTAG, "onStateChanged(" + state + ")");
-        if (notSelfManaged()) {
+        if (notSelfManaged(context)) {
             if (state == STATE_DIALING) {
                 requireAppRtcAudioManager().startRingBack();
             } else {
@@ -432,18 +442,24 @@ public class CallIntegration extends Connection {
         callback.onAudioDeviceChanged(selectedAudioDevice, availableAudioDevices);
     }
 
-    public static boolean selfManaged() {
+    private boolean selfManaged() {
-        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;
+        return selfManaged(context);
     }
 
-    public static boolean notSelfManaged() {
+    public static boolean selfManaged(final Context context) {
-        return Build.VERSION.SDK_INT < Build.VERSION_CODES.O;
+        final var packageManager = context.getPackageManager();
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
+                && packageManager.hasSystemFeature(PackageManager.FEATURE_TELEPHONY);
+    }
+
+    public static boolean notSelfManaged(final Context context) {
+        return !selfManaged(context);
     }
 
     public void setInitialAudioDevice(final AudioDevice audioDevice) {
         Log.d(Config.LOGTAG, "setInitialAudioDevice(" + audioDevice + ")");
         this.initialAudioDevice = audioDevice;
-        if (CallIntegration.selfManaged()) {
+        if (selfManaged()) {
             // once the 'CallIntegration' gets added to the system we receive calls to update audio
             // state
             return;

src/main/java/eu/siacs/conversations/services/CallIntegrationConnectionService.java

@@ -314,7 +314,7 @@ public class CallIntegrationConnectionService extends ConnectionService {
             final Account account,
             final Jid with,
             final Set<Media> media) {
-        if (CallIntegration.selfManaged()) {
+        if (CallIntegration.selfManaged(service)) {
             final var extras = new Bundle();
             extras.putParcelable(
                     TelecomManager.EXTRA_PHONE_ACCOUNT_HANDLE, getHandle(service, account));
@@ -349,7 +349,7 @@ public class CallIntegrationConnectionService extends ConnectionService {
 
     public static void addNewIncomingCall(
             final Context context, final AbstractJingleConnection.Id id) {
-        if (CallIntegration.notSelfManaged()) {
+        if (CallIntegration.notSelfManaged(context)) {
             Log.d(
                     Config.LOGTAG,
                     "not adding incoming call to TelecomManager on Android "

src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java

@@ -1692,7 +1692,7 @@ public class JingleRtpConnection extends AbstractJingleConnection
         ringingTimeoutFuture =
                 jingleConnectionManager.schedule(
                         this::ringingTimeout, BUSY_TIME_OUT, TimeUnit.SECONDS);
-        if (CallIntegration.selfManaged()) {
+        if (CallIntegration.selfManaged(xmppConnectionService)) {
             return;
         }
         xmppConnectionService.getNotificationService().startRinging(id, getMedia());