non-mainline telephony related AIDL refactor/decoupling

1. decouple IOnSubscriptionChangedListener AIDL from telephonyMainline
2. other refactor. moving APIs which will not be included in
telephony mainline to frameworks/base/core/java/android/telephony.
Moving internal classes like AIDL which will not be included in
telephony mainline to
framework/base/core/java/com/android/internal/telephony

Bug: 140908357
Test: Build & unit test
Change-Id: I9413ef758cceadd251d03f3b5ea1054cc48ef044
Merged-In: I9413ef758cceadd251d03f3b5ea1054cc48ef044
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index a8c1216..bf417ea 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -63,6 +63,7 @@
 import android.os.UserManager;
 import android.os.storage.StorageManager;
 import android.provider.MediaStore;
+import android.telephony.TelephonyRegistryManager;
 import android.util.AttributeSet;
 import android.view.Display;
 import android.view.DisplayAdjustments;
@@ -4747,7 +4748,7 @@
 
     /**
      * Use with {@link #getSystemService(String)} to retrieve an
-     * {@link android.os.telephony.TelephonyRegistryManager}.
+     * {@link TelephonyRegistryManager}.
      * @hide
      */
     @SystemApi