Fix issues with video on some phones

Signed-off-by: Mario Danic <mario@lovelyhq.com>

app/src/main/java/com/nextcloud/talk/activities/CallActivity.java

@@ -226,9 +226,9 @@ public class CallActivity extends AppCompatActivity {
 
         requestWindowFeature(Window.FEATURE_NO_TITLE);
         getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN |
-                View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
-                | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
-                | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
+                WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON |
+                WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
+                WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
         getWindow().getDecorView().setSystemUiVisibility(getSystemUiVisibility());
 
         setContentView(R.layout.activity_call);