Add the systemserver_fragment to permission SDK.

Note: This needs to be exported from the APEX (ag/15938066) when a new
prebuilt is dropped.

The systemserver_fragment is needed for dexpreopting when the permission
APEX is built from a prebuilt.

Bug: 194150908
Test: m nothing
Merged-In: Iae4fc725d486178d58fba76b3dc014c523317cb9
Change-Id: Iae4fc725d486178d58fba76b3dc014c523317cb9
(cherry picked from commit 529c5b5d)