Remove hardcoded package name.

Removed the hardcoded package name in account_preferences.xml.  Now we launch
the PreferenceScreen with only the action.  Added an intent-filter to the
preference screen to catch it.

Bug 2447903
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 1828a03..24e12c8 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -123,6 +123,10 @@
             android:name=".activity.setup.AccountSettings"
             android:label="@string/account_settings_action"
             >
+            <intent-filter>
+                <action android:name="com.android.email.activity.setup.ACCOUNT_MANAGER_ENTRY" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
         </activity>
         <activity
             android:name=".activity.setup.AccountSecurity"