When TARGET_FLATTEN_APEX=true, APEX files are not packaged in *.apex
files but flattened to the system partition under /system/apex/<name>
directories. There was a bug that those flattened files are not labeled
because the per-APEX file_contexts were applied only when building
*.apex. Fixing this by converting the file_contexts files so that
/system/apex/<name> path is prepended and applying the generated
file_contexts file for system.img when TARGET_FLATTEN_APEX=true.
Bug: 123314817
Test: TARGET_FLATTEN_APEX=true m
ls -alZ /system/apex/*/* shows that the files are correctly labeled
Change-Id: Ia82740a1da0083d5bcfd71354a6d374d2a918342
system/sepolicy/Android.mk has become too large (~2k lines) and hard to
navigate. This patch reorganizes build rules for convenience. No
functional changes are made.
Test: m selinux_policy
Change-Id: I9a022b223b2387a4475da6d8209d561bfea228fb
