Set min_sdk_version for the Widevine APEX

also remove `use_vndk_as_stable: true` to remove dependency to VNDK
libs.

Bug: 251299786
Test: build WV APEX with V and install it on U device
Change-Id: Ie7f7f9b699119478d4b33f95ab9e6ba7f459346c

libwvdrmengine/cdm/core/src/Android.bp

@@ -35,4 +35,5 @@ cc_library {
     static_libs: ["libcdm_metrics_protos"],
     whole_static_libs: ["libcdm_metrics_protos"],
     export_static_lib_headers: ["libcdm_metrics_protos"],
+    min_sdk_version: "UpsideDownCake",
 }