Make Security_patch an `android_filesystem` property

Make-built partitions use partition specific security_patches for
build_image, but Soong-built partitions currently use the platform
security patch for all partitions (including vendor,odm,...). This CL
introduces a `Security_patch` property to set this value explicity. The
name and description have been copied from `bootimg`.

This CL also updates `fsgen` to set this property on the autogenerated
partitions. The logic has been copied from `build/make/core/Makefile`.
It is currently missing `boot` and `init_boot` (I have not tested
bit-identical for those partitions yet).

Bug: 383357338
Test: lunch aosp_cf_x86_64_phone-trunk_staging-userdebug
Setup
- export COPY_IMAGES_FOR_TARGET_FILES_ZIP=true
- export BUILD_DATETIME=10
- commented out installed_*_notice_xml_gz in build/make/core/Makefile
Test: verified that the following .img files are bit identical in top of
CL stack
odm,system_dlkm,vendor_dlkm,odm_dlkm

Change-Id: I9ae9bf957ffd479c57f12a49864589d285d93a71
diff --git a/android/variable.go b/android/variable.go
index 69e0337..3cf66ea 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -617,7 +617,11 @@
 	ProductUseDynamicPartitionSize bool   `json:",omitempty"`
 	CopyImagesForTargetFilesZip    bool   `json:",omitempty"`
 
-	VendorSecurityPatch string `json:",omitempty"`
+	VendorSecurityPatch     string `json:",omitempty"`
+	OdmSecurityPatch        string `json:",omitempty"`
+	SystemDlkmSecurityPatch string `json:",omitempty"`
+	VendorDlkmSecurityPatch string `json:",omitempty"`
+	OdmDlkmSecurityPatch    string `json:",omitempty"`
 
 	// Boot image stuff
 	BuildingRamdiskImage            bool     `json:",omitempty"`