android: enable MTE on devices that declare having it

Android.bp

@@ -73,6 +73,9 @@ cc_library {
         debuggable: {
             cflags: ["-DLABEL_MEMORY"],
         },
+        device_has_arm_mte: {
+            cflags: ["-DHAS_ARM_MTE", "-march=armv9-a+memtag"]
+        },
     },
     apex_available: [
         "com.android.runtime",