Add a new Soong config variable EMMA_INSTRUMENT

This change introduces a new Soong config variable named
`EMMA_INSTRUMENT`. This variable mirrors the behavior of the existing
`EMMA_INSTRUMENT` condition in Android.mk files, allowing for
conditional build configurations based on whether EMMA instrumentation
is enabled.

Bug: 342330305
Test: 1) EMMA_INSTRUMENT=true m ahat-tests
      2) m -j ahat-tests
Change-Id: I7bc28cd3de936d1e6bfb218683bcf07b40e80784
diff --git a/core/android_soong_config_vars.mk b/core/android_soong_config_vars.mk
index 5fc8fd4..48667ac 100644
--- a/core/android_soong_config_vars.mk
+++ b/core/android_soong_config_vars.mk
@@ -47,6 +47,8 @@
 $(call soong_config_set_bool,ANDROID,CLANG_COVERAGE,$(CLANG_COVERAGE))
 $(call soong_config_set,ANDROID,SCUDO_ALLOCATION_RING_BUFFER_SIZE,$(PRODUCT_SCUDO_ALLOCATION_RING_BUFFER_SIZE))
 
+$(call soong_config_set_bool,ANDROID,EMMA_INSTRUMENT,$(if $(filter true,$(EMMA_INSTRUMENT)),true,false))
+
 # PRODUCT_PRECOMPILED_SEPOLICY defaults to true. Explicitly check if it's "false" or not.
 $(call soong_config_set_bool,ANDROID,PRODUCT_PRECOMPILED_SEPOLICY,$(if $(filter false,$(PRODUCT_PRECOMPILED_SEPOLICY)),false,true))