Expose clearCapabilities for mainline module

Support telephony mainline module usage.

Bug: 138306002
Test: Build and make api-stubs-docs-update-current-api
Change-Id: I6260695b01ec06244d2822f9438a7fae83539ff2
Merged-In: I0a462da4e87cae2c7d4a9b9a92de061a086c5752
diff --git a/core/java/android/net/NetworkRequest.java b/core/java/android/net/NetworkRequest.java
index 0c83368..c7b3009 100644
--- a/core/java/android/net/NetworkRequest.java
+++ b/core/java/android/net/NetworkRequest.java
@@ -247,9 +247,8 @@
          * removing even the capabilities that are set by default when the object is constructed.
          *
          * @return The builder to facilitate chaining.
-         * @hide
          */
-        @UnsupportedAppUsage
+        @NonNull
         public Builder clearCapabilities() {
             mNetworkCapabilities.clearAll();
             return this;