Add the systemserver_fragment to media SDK.

Note: This needs to be exported from the APEX (ag/15937385) when a new
prebuilt is dropped.

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

Bug: 194150908
Test: m nothing
Merged-In: I2cca8b206451858e636c6bd04617cf3933f702c6
Change-Id: I2cca8b206451858e636c6bd04617cf3933f702c6
(cherry picked from commit 381fb640)