shusky: Add build_flags based properties for SMR/EMR build

Flag: build.RELEASE_IS_SMR
Flag: build.RELEASE_IS_EMR
Flag: build.RELEASE_BASE_OS_HUSKY
Flag: build.RELEASE_BASE_OS_SHIBA
Bug: 155105803
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:28a1b27468d204366837ce4ce8e2e5559ac6bf2a)
Merged-In: Ibec4f0c908089ca4304e59e9d37529fa2d4fa40d
Change-Id: Ibec4f0c908089ca4304e59e9d37529fa2d4fa40d
2 files changed