Remove ANDROID_EXPERIMENTAL_MTE.

Now that the feature guarded by this flag has landed in Linux 5.10
we no longer need the flag, so we can remove it.

Bug: 135772972
Change-Id: I02fa50848cbd0486c23c8a229bb8f1ab5dd5a56f
diff --git a/core/soong_config.mk b/core/soong_config.mk
index 5b2d1dc..48ab0eb 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -103,8 +103,6 @@
 $(call add_json_list, CFIIncludePaths,                   $(CFI_INCLUDE_PATHS) $(PRODUCT_CFI_INCLUDE_PATHS))
 $(call add_json_list, IntegerOverflowExcludePaths,       $(INTEGER_OVERFLOW_EXCLUDE_PATHS) $(PRODUCT_INTEGER_OVERFLOW_EXCLUDE_PATHS))
 
-$(call add_json_bool, Experimental_mte,                  $(filter true,$(TARGET_EXPERIMENTAL_MTE)))
-
 $(call add_json_bool, DisableScudo,                      $(filter true,$(PRODUCT_DISABLE_SCUDO)))
 
 $(call add_json_bool, ClangTidy,                         $(filter 1 true,$(WITH_TIDY)))