Blueberry2: Add SL4A Abstractions

 - Advertiser
 - Scanner
 - Security

Bug: 236301249
Test: mma -j $(nproc)
Test: system/gd/cert/run --clean --sl4a_sl4a
Tag: #stability
Change-Id: I88f366fb43b99d89e3e194d4b0fcf3bea0c5f1a6
Merged-In: I88f366fb43b99d89e3e194d4b0fcf3bea0c5f1a6