Allow association to debug target app

Tests, development tools are currently broken, so this fix helps such
test code to connect with a debuggable version of AiAi.

Fix: When a system app with allowed associations is updated, we will
     track the android:debuggable flas for such apps.

Change-Id: I917252f8d524346ec69cfd9f642bd1eee4e5aba6
Test: Using AiAi debuggable with test app connects properly
Test: Using AiAi factory with test app does not connect at all
Test: http://sponge/c5680acc-b650-4542-95e6-c40a67ab341f
Test:
     adb shell  dumpsys activity allowed-associations
     ACTIVITY MANAGER ALLOWED ASSOCIATION STATE (dumpsys activity
     allowed-associations)
       Allowed associations (by restricted package):
       * com.google.android.as:
   	Allow: com.android.providers.telephony
	Allow: com.google.android.googlequicksearchbox
	Allow: com.android.systemui.navbarhint
	Allow: com.google.android.gms
	Allow: com.google.android.gsf
	Allow: com.google.android.apps.nexuslauncher
	Allow: com.android.systemui
	Allow: com.android.providers.contacts
	(debuggable)