opt-in to MTE async mode

currently only benefits GrapheneOS users on Pixel 8 and 9 who don't turn on MTE for all apps or Molly manually. hopefully will be extended to all Pixel users and then more devices

app/src/main/AndroidManifest.xml

@@ -97,6 +97,7 @@
     <application android:name=".ApplicationContext"
                  android:icon="@mipmap/ic_launcher"
                  android:label="@string/app_name"
+                 android:memtagMode="async"
                  android:supportsRtl="true"
                  android:resizeableActivity="true"
                  android:fullBackupOnly="false"