[security] SubscriptionGroup is exposed to unprivileged callers

SubscriptionInfo.mGroupUUID is not cleared in
conditionallyRemoveIdentifiers if the caller only has READ_PHONE_STATE
(based on a check to checkReadPhoneState) and not READ_DEVICE_IDENTIFIERS.
Bug: 181053462
Test: atest SubscriptionManagerTest

Change-Id: Ic2b62523330dc6e2169ad851715c4ab3da3b29cf
Merged-In: Ic2b62523330dc6e2169ad851715c4ab3da3b29cf
(cherry picked from commit 219d284a68f56093aa9ca6610a4999b35c4cf5a9)

telephony/java/android/telephony/SubscriptionInfo.java

diff --git a/telephony/java/android/telephony/SubscriptionInfo.java b/telephony/java/android/telephony/SubscriptionInfo.java
index 0ee6568b..90d7a16 100644
--- a/telephony/java/android/telephony/SubscriptionInfo.java
+++ b/telephony/java/android/telephony/SubscriptionInfo.java
@@ -569,6 +569,13 @@
     /**
      * @hide
      */
+    public void clearGroupUuid() {
+        this.mGroupUUID = null;
+    }
+
+    /**
+     * @hide
+     */
     public List<String> getEhplmns() {
         return mEhplmns == null ? Collections.emptyList() : Arrays.asList(mEhplmns);
     }