Remove "rebootless" related stuff

The widevine apex is supposed to be installed in a "staged" way.

- apex_manifest: remove supportsRebootlessUpdate flag
- .rc: remove apex.com.google.android.widevine.ready=true

Bug: 243333942
Test: m
Change-Id: Ibb963937e6d8d889d9281d22972e12a148f59b94

libwvdrmengine/apex/apex_manifest.json

@@ -1,5 +1,4 @@
 {
     "name": "com.google.android.widevine",
-    "version": 1,
-    "supportsRebootlessUpdate": true
+    "version": 1
 }