More hardening

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

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

@@ -1016,6 +1016,8 @@ public class CallActivity extends AppCompatActivity {
                 videoCapturer = null;
             }
 
+            rootEglBase.release();
+
             hangupNetworkCalls();
 
         }
@@ -1207,6 +1209,8 @@ public class CallActivity extends AppCompatActivity {
         MagicPeerConnectionWrapper magicPeerConnectionWrapper;
         if ((magicPeerConnectionWrapper = getPeerConnectionWrapperForSessionId(sessionId)) != null) {
             runOnUiThread(() -> removeMediaStream(sessionId));
+            magicPeerConnectionWrapper.removeMediaStream();
+            magicPeerConnectionWrapper.removePeerConnection();
             deleteMagicPeerConnection(magicPeerConnectionWrapper);
         }
     }

app/src/main/java/com/nextcloud/talk/webrtc/MagicPeerConnectionWrapper.java

@@ -92,6 +92,10 @@ public class MagicPeerConnectionWrapper {
         }
     }
 
+    public void removePeerConnection() {
+        peerConnection.close();
+        peerConnection = null;
+    }
     public void removeMediaStream() {
         if (peerConnection != null && localMediaStream != null) {
             peerConnection.removeStream(localMediaStream);