Add NetworkProviderTest#testRegisterNetworkOffer back into test

This test was temporarily disabled because prebuilt module is not
updated in the branch. Now the prebuilt was S already, so add the
test back to test to ensure the coverage.

Test: atest FrameworksNetTests CtsNetTestCases
Bug: 189074532
Change-Id: I510f457d2869c2904404fe7ef55828e84636e4c5
diff --git a/tests/common/java/android/net/NetworkProviderTest.kt b/tests/common/java/android/net/NetworkProviderTest.kt
index 626a344..ff5de1d 100644
--- a/tests/common/java/android/net/NetworkProviderTest.kt
+++ b/tests/common/java/android/net/NetworkProviderTest.kt
@@ -40,7 +40,6 @@
 import com.android.testutils.isDevSdkInRange
 import org.junit.After
 import org.junit.Before
-import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -205,7 +204,6 @@
         }
     }
 
-    @Ignore("Temporarily disable the test since prebuilt Connectivity module is not updated.")
     @IgnoreUpTo(Build.VERSION_CODES.R)
     @Test
     fun testRegisterNetworkOffer() {