gn2bp: Make update_results parse desc_arm.json

Test: lunch aosp_arm && m cronet_aml_components_cronet_android_cronet
Test: lunch aosp_cf_x86_phone && m cronet_aml_components_cronet_android_cronet
Test: lunch aosp_cf_x86_64_phone && m cronet_aml_components_cronet_android_cronet
Change-Id: I6dc2345c66d784a52c7389c823c06962fa0e74d6
2 files changed