soong_config: Add flag for devices use metadata as FDE key

Change-Id: I5f70280e72613a8f850cb3263c45e95e80cb8b3c
Signed-off-by: Erfan Abdi <erfangplus@gmail.com>
diff --git a/build/soong/android/variable.go b/build/soong/android/variable.go
index 0569d20..d2f2e5b 100644
--- a/build/soong/android/variable.go
+++ b/build/soong/android/variable.go
@@ -6,9 +6,13 @@
 	TargetNeedsHWCOnFirstRef struct {
 		Cflags []string
 	}
+	Uses_metadata_as_fde_key struct {
+		Cflags []string
+	}
 }
 
 type ProductVariables struct {
 	Healthd_use_battery_info  *bool `json:",omitempty"`
 	TargetNeedsHWCOnFirstRef  *bool `json:",omitempty"`
+	Uses_metadata_as_fde_key  *bool `json:",omitempty"`
 }
diff --git a/build/soong/soong_config.mk b/build/soong/soong_config.mk
index 24564a0..ab056c5 100644
--- a/build/soong/soong_config.mk
+++ b/build/soong/soong_config.mk
@@ -5,6 +5,7 @@
 # See build/core/soong_config.mk for the add_json_* functions you can use here.
 $(call add_json_bool, Healthd_use_battery_info, $(filter true,$(HEALTHD_USE_BATTERY_INFO)))
 $(call add_json_bool, TargetNeedsHWCOnFirstRef, $(filter true,$(TARGET_NEEDS_HWC_ONFIRSTREF)))
+$(call add_json_bool, Uses_metadata_as_fde_key, $(filter true,$(TARGET_USES_METADATA_AS_FDE_KEY)))
 
 # This causes the build system to strip out the last comma in our nested struct, to keep the JSON valid.
 _contents := $(_contents)__SV_END