Add make support for Aml_abis and Ndk_abis options

Add a new TARGET_ARCH_SUITE which, when set to 'mainline_sdk' or 'ndk',
sets `Aml_abis: true` in soong.variables.

This is required to enable removing the custom soong.variables that
are being maintained for the ndk and mainline sdk builds.

Bug: 174315599
Test: TARGET_ARCH_SUITE=mainline-sdk m nothing; inspect soong.variables
      (ditto for ndk)
Change-Id: Ib651a637457310270840d721cdccf50bede3ee58
diff --git a/core/soong_config.mk b/core/soong_config.mk
index 61c0452..9459a5b 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -54,6 +54,9 @@
 $(call add_json_str,  DeviceSecondaryCpuVariant,         $(TARGET_2ND_CPU_VARIANT))
 $(call add_json_list, DeviceSecondaryAbi,                $(TARGET_2ND_CPU_ABI) $(TARGET_2ND_CPU_ABI2))
 
+$(call add_json_bool, Aml_abis,                          $(if $(filter mainline_sdk,$(TARGET_ARCH_SUITE)),true))
+$(call add_json_bool, Ndk_abis,                          $(if $(filter ndk,         $(TARGET_ARCH_SUITE)),true))
+
 $(call add_json_str,  NativeBridgeArch,                  $(TARGET_NATIVE_BRIDGE_ARCH))
 $(call add_json_str,  NativeBridgeArchVariant,           $(TARGET_NATIVE_BRIDGE_ARCH_VARIANT))
 $(call add_json_str,  NativeBridgeCpuVariant,            $(TARGET_NATIVE_BRIDGE_CPU_VARIANT))