Android: Fix a possible crash when main recreates

android/app/src/main/java/com/github/stenzek/duckstation/AndroidHostInterface.java

@@ -41,6 +41,10 @@ public class AndroidHostInterface {
         }
     }
 
+    public void setContext(Context context) {
+        mContext = context;
+    }
+
     static public native String getScmVersion();
 
     static public native String getFullScmVersion();

android/app/src/main/java/com/github/stenzek/duckstation/MainActivity.java

@@ -175,6 +175,7 @@ public class MainActivity extends AppCompatActivity {
             throw new RuntimeException("Failed to create host interface");
         }
 
+        AndroidHostInterface.getInstance().setContext(this);
         mGameList.refresh(false, false, this);
     }