Add config_defaultRoleHolders for specifying default role holders.

This config string array will be an array of roles and package names
of their default holders, with each item in the format of "ROLE_NAME:
PACKAGE_NAME_1, PACKAGE_NAME_2". This config will be read by
PermissionController to initialize the roles. This change also fixed
an issue preventing role controller to set default holders correctly.

Bug: 110557011
Bug: 122730135
Test: build
Change-Id: I90ffd156d26098235c821e7937950c0b420e0e7f
diff --git a/services/core/java/com/android/server/policy/role/LegacyRoleResolutionPolicy.java b/services/core/java/com/android/server/policy/role/LegacyRoleResolutionPolicy.java
index 45c975b..055c941 100644
--- a/services/core/java/com/android/server/policy/role/LegacyRoleResolutionPolicy.java
+++ b/services/core/java/com/android/server/policy/role/LegacyRoleResolutionPolicy.java
@@ -62,6 +62,8 @@
                         mContext.getContentResolver(),
                         Settings.Secure.SMS_DEFAULT_APPLICATION, userId);
 
+                // TODO: STOPSHIP: Remove the following code once we remove default_sms_application
+                // and use the new config_defaultRoleHolders.
                 if (result == null) {
                     Collection<SmsApplication.SmsApplicationData> applications =
                             SmsApplication.getApplicationCollectionAsUser(mContext, userId);