Remove api_dir property

The api_dir property is removed, and the api dir path for aidl_interface
is fixed to aidl_api/{module_name}. According to this rule, all api dirs
are moved to aidl_api/{module_name}.

Bug: 113134692
Test: m -j
Change-Id: I4f33be49fd205a611b243f31564524352b073204
Merged-In: I4f33be49fd205a611b243f31564524352b073204
(cherry picked from commit 3bc77c2815d5c18c12afe6312e2cd6853bca79f0)
16 files changed