Rename libkeymaster to libkeymaster_staging

Fix a build breakage by renaming libkeymaster to
libkeymaster_staging. fugu's vendor tree already had
a libkeymaster.so which masked system/keymaster/libkeymaster.

Bug: 37997750
Change-Id: Ie478726bf81e965be64fb913844b881064e9b66c
1 file changed