Fix some TetheringCoverageTest failure

1. Fix no ACCESS_NETWORK_STATE permission problem when accessing
EthernetManager#getAvailableInterfaces API from S.
2. Fix some wrong jarjar rules.

Bug: 187371740
Test: atest TetheringCoverageTest on R platform
Change-Id: I203db6c4ea2e13d8fb5bc2db7ee877ccbb97b761
diff --git a/Tethering/tests/jarjar-rules.txt b/Tethering/tests/jarjar-rules.txt
index c99ff7f..9cb143e 100644
--- a/Tethering/tests/jarjar-rules.txt
+++ b/Tethering/tests/jarjar-rules.txt
@@ -1,8 +1,8 @@
 # Don't jar-jar the entire package because this test use some
 # internal classes (like ArrayUtils in com.android.internal.util)
 rule com.android.internal.util.BitUtils* com.android.networkstack.tethering.util.BitUtils@1
-rule com.android.internal.util.IndentingPrintWriter.java* com.android.networkstack.tethering.util.IndentingPrintWriter.java@1
-rule com.android.internal.util.IState.java* com.android.networkstack.tethering.util.IState.java@1
+rule com.android.internal.util.IndentingPrintWriter* com.android.networkstack.tethering.util.IndentingPrintWriter@1
+rule com.android.internal.util.IState* com.android.networkstack.tethering.util.IState@1
 rule com.android.internal.util.MessageUtils* com.android.networkstack.tethering.util.MessageUtils@1
 rule com.android.internal.util.State* com.android.networkstack.tethering.util.State@1
 rule com.android.internal.util.StateMachine* com.android.networkstack.tethering.util.StateMachine@1