ionic-team#8182 Add missing null checks in BridgeActivity

Author: theigl

android/capacitor/src/main/java/com/getcapacitor/BridgeActivity.java

@@ -66,7 +66,9 @@ public Bridge getBridge() {
     @Override
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
-        bridge.saveInstanceState(outState);
+		if (bridge != null) {
+			bridge.saveInstanceState(outState);
+		}
     }
 
     @Override
@@ -82,8 +84,10 @@ public void onStart() {
     @Override
     public void onRestart() {
         super.onRestart();
-        this.bridge.onRestart();
-        Logger.debug("App restarted");
+		if (this.bridge != null) {
+			this.bridge.onRestart();
+			Logger.debug("App restarted");
+		}
     }
 
     @Override
@@ -131,7 +135,9 @@ public void onDestroy() {
     @Override
     public void onDetachedFromWindow() {
         super.onDetachedFromWindow();
-        this.bridge.onDetachedFromWindow();
+		if (this.bridge != null) {
+			this.bridge.onDetachedFromWindow();
+		}
     }
 
     /**