Update recommended way to suppress @UnstableApi errors in lint.xml

#minor-release

PiperOrigin-RevId: 582599098

Author: icbaker

libraries/common/src/main/java/androidx/media3/common/util/UnstableApi.java

@@ -95,8 +95,7 @@
  * <?xml version="1.0" encoding="utf-8"?>
  * <lint>
  *   <issue id="UnsafeOptInUsageError">
- *     <ignore
- *         regexp='\(markerClass = androidx\.media3\.common\.util\.UnstableApi\.class\)' />
+ *     <option name="opt-in" value="androidx.media3.common.util.UnstableApi" />
  *   </issue>
  * </lint>
  * }</pre>

lint.xml libraries/lint.xml

@@ -15,9 +15,6 @@
 -->
 <lint>
   <issue id="UnsafeOptInUsageError">
-    <ignore path='libraries/'
-      regexp='\(markerClass = androidx\.media3\.common\.util\.UnstableApi\.class\)' />
-    <ignore path='testapps/'
-      regexp='\(markerClass = androidx\.media3\.common\.util\.UnstableApi\.class\)' />
+    <option name="opt-in" value="androidx.media3.common.util.UnstableApi" />
   </issue>
 </lint>