Revert "soong_config: Add flag for devices use metadata as FDE key"

* Qcom reverted the relevant commit in cryptfs_hw

This reverts commit a4d6ce67e7.

Change-Id: Ife1812ebc80946953e3d1a558617c94ddbc7fad4

build/soong/android/variable.go

@@ -40,9 +40,6 @@ type Product_variables struct {
 	Uses_generic_camera_parameter_library struct {
 		Srcs []string
 	}
-	Uses_metadata_as_fde_key struct {
-		Cflags []string
-	}
 	Uses_nvidia_enhancements struct {
 		Cppflags []string
 	}
@@ -89,7 +86,6 @@ type ProductVariables struct {
 	Target_process_sdk_version_override  *string `json:",omitempty"`
 	Target_shim_libs  *string `json:",omitempty"`
 	Uses_generic_camera_parameter_library  *bool `json:",omitempty"`
-	Uses_metadata_as_fde_key  *bool `json:",omitempty"`
 	Uses_nvidia_enhancements  *bool `json:",omitempty"`
 	Uses_qcom_bsp_legacy  *bool `json:",omitempty"`
 	Uses_qti_camera_device  *bool `json:",omitempty"`