Allow selecting a different product in banchan.

Necessary since the products used for APEX modules are different in
internal builds.

Test: banchan com.android.art
Test: banchan com.android.art arm
Test: banchan com.android.art art_module_arm
Test: banchan com.android.art module_arm
Test: banchan com.android.art x86_64
Test: banchan com.android.art art_module_x86_64
Bug: 179779520
Change-Id: Ib59a86b70e409537aaad7258465b6874b589b858