Move RCS table creation flag to contract class

This will allow access to the flag outside of the test package. In
particular, we can now use this flag to disable the relevant CTS tests
when RCS tables are not created.

Test: Manually ensured the flag works using CtsRcsTestCases
Change-Id: I995f38c83d52c3a23131f223a550cf71e59b9cba
diff --git a/telephony/java/android/provider/Telephony.java b/telephony/java/android/provider/Telephony.java
index 51c8f65..50b8f79 100644
--- a/telephony/java/android/provider/Telephony.java
+++ b/telephony/java/android/provider/Telephony.java
@@ -2059,6 +2059,11 @@
      * @hide - not meant for public use
      */
     public interface RcsColumns {
+        // TODO(sahinc): Turn this to true once the schema finalizes, so that people can update
+        //  their messaging databases. NOTE: move the switch/case update in MmsSmsDatabaseHelper to
+        //  the latest version of the database before turning this flag to true.
+        boolean IS_RCS_TABLE_SCHEMA_CODE_COMPLETE = false;
+
         /**
          * The authority for the content provider
          */