Self-Managed Incoming Call Disambiguation UX.

- Handle auto-disconnect of foreground call when answering a self-managed
call.
- Enforce restriction that the PhoneAccount associated with a self-managed
CS must have a label which is the app's name.
- Ensure self-managed phone accounts can't be registered with
call provider, connection manager, or sim sub capabilities.
- Add "incoming call" UX which is shown when a new incoming call from a
self-managed CS comes in and there is an existing call for another CS.

Test: Unit, manual
Bug: 34159263
Change-Id: I371be9baa6f56c77aa83349977c0131f0e319047
diff --git a/testapps/AndroidManifest.xml b/testapps/AndroidManifest.xml
index cc6470e..ec49696 100644
--- a/testapps/AndroidManifest.xml
+++ b/testapps/AndroidManifest.xml
@@ -169,7 +169,8 @@
 
         <activity android:name="com.android.server.telecom.testapps.SelfManagedCallingActivity"
                   android:label="@string/selfManagedCallingActivityLabel"
-                  android:process="com.android.server.telecom.testapps.SelfMangingCallingApp">
+                  android:process="com.android.server.telecom.testapps.SelfMangingCallingApp"
+                  android:theme="@android:style/Theme.Material.Light">
           <intent-filter>
               <action android:name="android.intent.action.MAIN" />
               <category android:name="android.intent.category.DEFAULT" />