Should the name of the main activity be .MainActivity?

In my application there is this main action:

<activity
    android:name=".main.MainActivity"
    ...
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

and it starts without problems with a home launcher. However, when I try to start it from Google Gesture Search, I get a Gesture error message that says the application does not have one .MainActivity.

https://play.google.com/store/apps/details?id=com.google.android.apps.gesturesearch

Are Android apps needed for the core business .MainActivity? If not, is this a soft recommendation or agreement or just a bad assumption about the Gesture part?