Replace get*PhoneAccounts* public API methods with new method (1/3)

Hide getCallCapablePhoneAccounts and getPhoneAccountsSupportingScheme
because a third party app should not be able to see all phone accounts
registered. Replace instead with getPhoneAccountsForPackage(Context)
which will only return the phone accounts registered by a particular package.

Bug: 17510811
Change-Id: I8465ef4f13b62fe83f51835cfffe1656298041a8
diff --git a/telecomm/java/android/telecom/Call.java b/telecomm/java/android/telecom/Call.java
index 1a6c52f..b0b6fb9 100644
--- a/telecomm/java/android/telecom/Call.java
+++ b/telecomm/java/android/telecom/Call.java
@@ -80,6 +80,15 @@
      */
     public static final int STATE_CONNECTING = 9;
 
+    /**
+     * The key to retrieve the optional {@code PhoneAccount}s Telecom can bundle with its Call
+     * extras. Used to pass the phone accounts to display on the front end to the user in order to
+     * select phone accounts to (for example) place a call.
+     *
+     * @hide
+     */
+    public static final String AVAILABLE_PHONE_ACCOUNTS = "selectPhoneAccountAccounts";
+
     public static class Details {
         private final Uri mHandle;
         private final int mHandlePresentation;