Delete ParcelableString, add StringParceledListSlice

Both inherit from package private BaseParceledListSlice.

This is still bad, but it's not as bad. The existing code that uses
this can just do Foo.bar().getList() now instead of having to marshal
to and from an oddball type at either end as well.

In the longer term ParceledListSlice<> should be eliminated, but it's
not clear how far into the future that is going to happen.

Test: runtest -x services/tests/servicestests/src/com/android/server/devicepolicy/DevicePolicyManagerTest.java
Test: runtest -x core/tests/coretests/src/android/content/pm/ParceledListSliceTest.java
Change-Id: Ie69b96b5215d6e04990f6d31345772cdfee21d78

keystore/java/android/security/IKeyChainService.aidl

@@ -15,7 +15,7 @@
  */
 package android.security;
 
-import android.content.pm.ParceledListSlice;
+import android.content.pm.StringParceledListSlice;
 
 /**
  * Caller is required to ensure that {@link KeyStore#unlock
@@ -39,8 +39,8 @@ interface IKeyChainService {
     // APIs used by Settings
     boolean deleteCaCertificate(String alias);
     boolean reset();
-    ParceledListSlice getUserCaAliases();
-    ParceledListSlice getSystemCaAliases();
+    StringParceledListSlice getUserCaAliases();
+    StringParceledListSlice getSystemCaAliases();
     boolean containsCaAlias(String alias);
     byte[] getEncodedCaCertificate(String alias, boolean includeDeletedSystem);
     List<String> getCaCertificateChainAliases(String rootAlias, boolean includeDeletedSystem);