gn2bp: Convert genrules to cc_genrules

* This change doesn't effectively use the `CC_ARCH` environment variable. Just a change of variable name.
* cc_genrules are compiled so they need host_supported/device_supported tags.

Test: m cronet_aml_components_cronet_android_cronet
Change-Id: Ie55e5e0fb60b444817bc13c967e89f35c4e8badf
3 files changed