Impelement "Share to LOVE" support.

This allows you to share either .love game to launch as game (for the
non-fused APKs and instance of LOVE isn't running) or any file that
gets passed as love.filedropped.

Caveat: Ensure the intended game is running before sending files to LOVE app.
Otherwise, LOVE will attempt to open it as *.love file, which is may not what
you want.

app/src/main/AndroidManifest.xml

@@ -32,7 +32,7 @@
             android:exported="true"
             android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
             android:configChanges="orientation|screenSize|smallestScreenSize|screenLayout|keyboard|keyboardHidden|navigation"
-            android:launchMode="singleTask"
+            android:launchMode="singleInstance"
             android:screenOrientation="landscape">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -43,5 +43,19 @@
                 <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
             </intent-filter>
         </activity>
+        <activity
+            android:name=".IntentReceiverActivity"
+            android:exported="true"
+            android:theme="@android:style/Theme.Translucent.NoTitleBar"
+            android:taskAffinity=""
+            android:excludeFromRecents="true"
+            android:relinquishTaskIdentity="true">
+            <intent-filter>
+                <action android:name="android.intent.action.SEND" />
+                <category android:name="android.intent.category.OPENABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="*/*" />
+            </intent-filter>
+        </activity>
     </application>
 </manifest>