Add headers and macros for building VHAL server for AGL

It won't change the logic of Android codes.

Bug: 148877226
Bug: 150791171

Test: Android build won't break

Change-Id: I07006a4a3e20900a2fa90b84167d114f9ac45cfe
(cherry picked from commit 080963546aabc1ee9c06b5309f2d1dc1aec218f0)
Merged-In: I07006a4a3e20900a2fa90b84167d114f9ac45cfe
7 files changed