When flattened, the Make module for an APEX is a phony package for the
files in it. There is no output (either implcit or explicit) there.
Bug: 144338929
Test: m
Test: check the generated Android-<target>.mk file
Change-Id: I86df3b69f402a7e2d94bafa39f2aad3312d8c28b
override_apex module type is used to override existing apex module with
certain properties overridden. Currently, only the 'apps' property is
overridable.
Bug: 144338929
Test: m
Change-Id: Ic050b062093cda29ce78126cc92dd6097647f7db
apex.go is too big. Separate the build rule and android.mk generation
logic into builder.go and androidmk.go, respectively. prebuilt_apex is
moved to prebuilt.go as well.
No refactoring has been made other than the splitting.
Test: m
Change-Id: I839ab0a1ba2b70ce82d98ac1fa8e3534808b5fd3
