Remove @TestApi from @SystemApi symbols

I ran these commands:
    cd frameworks/base
    grep -rl '@TestApi' --include '*.java' | xargs perl -i -p0e \
        's/\@SystemApi[\s\n]+(\@\w+[\s\n]+)?\@TestApi/\@SystemApi\1/gs'
    grep -rl '@TestApi' --include '*.java' | xargs perl -i -p0e \
        's/\@TestApi[\s\n]+(\@\w+[\s\n]+)?\@SystemApi/\1\@SystemApi/gs'

Bug: 171179806
Test: m checkapi
Change-Id: I772790b783b0a8730b8bf680c9e569a886b8d789
Merged-In: I772790b783b0a8730b8bf680c9e569a886b8d789

core/java/android/net/EthernetManager.java

@@ -37,7 +37,6 @@ import java.util.concurrent.Executor;
  * @hide
  */
 @SystemApi
-@TestApi
 @SystemService(Context.ETHERNET_SERVICE)
 public class EthernetManager {
     private static final String TAG = "EthernetManager";