Fix improper use of JNI_ABORT for operations where Java objects are written.

In these RS API calls, it is possible (and very likely) that some Java objects
are written to via JNI calls into the RS driver. These writes can end up being
discarded if we specify JNI_ABORT, particularly if the Java object has been
moved due to GC. The change introduces a readonly mode for some macro calls
and updates other JNI callers to appropriately skip JNI_ABORT.

Change-Id: I8c5f2ae959b3fbc9008c9d2ac4542f2ebab29b06