start pip mode when back button is pressed

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/activities/MagicCallActivity.kt

@@ -89,13 +89,15 @@ class MagicCallActivity : BaseActivity() {
 
     }
 
-    @RequiresApi(Build.VERSION_CODES.O)
-    fun enterPipMode() {
-        enableKeyguard()
-        enterPictureInPictureMode(getPipParams())
+    override fun onBackPressed() {
+        enterPipMode()
     }
 
     override fun onUserLeaveHint() {
+        enterPipMode()
+    }
+
+    fun enterPipMode() {
         enableKeyguard()
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
             enterPictureInPictureMode(getPipParams())

app/src/main/java/com/nextcloud/talk/controllers/CallController.java

@@ -865,12 +865,7 @@ public class CallController extends BaseController {
 
     @OnClick(R.id.callControlEnterPip)
     void enterPipMode() {
-        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O){
-            ((MagicCallActivity) getActivity()).enterPipMode();
-        } else{
-            Log.w(TAG, "tried to enterPipMode with an android api level below 26 (Android 8). This scenario should " +
-                "have been avoided by hiding the PIP button!");
-        }
+        ((MagicCallActivity) getActivity()).enterPipMode();
     }
 
     @OnClick(R.id.callControlHangupView)