Remove protobuf dumping support from FaceService

Currently, FaceService supports a `--proto` flag for dumping protobuf
debug data to GMS core. This functionality is now redundant and presents
a privacy risk, so this commit removes support for it and deletes the
associated method.

Test: manual
1. Attach a device and run `adb shell dumpsys face --proto`
2. Without change, verify that this prints out binary protobuf data
3. With change, verify that the output is the same as `adb shell dumpsys
face` and contains no protobuf data

Fixes: 135954555
Change-Id: I4cb6215cdba0f080259a5f08ae910d6bfc6c0c80
diff --git a/services/core/java/com/android/server/biometrics/face/FaceService.java b/services/core/java/com/android/server/biometrics/face/FaceService.java
index 90edcb5..def7f75 100644
--- a/services/core/java/com/android/server/biometrics/face/FaceService.java
+++ b/services/core/java/com/android/server/biometrics/face/FaceService.java
@@ -54,7 +54,6 @@
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.util.Slog;
-import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.R;
 import com.android.internal.annotations.GuardedBy;
@@ -503,8 +502,6 @@
             try {
                 if (args.length > 1 && "--hal".equals(args[0])) {
                     dumpHal(fd, Arrays.copyOfRange(args, 1, args.length, args.getClass()));
-                } else if (args.length > 0 && "--proto".equals(args[0])) {
-                    dumpProto(fd);
                 } else {
                     dumpInternal(pw);
                 }
@@ -1296,49 +1293,6 @@
         mUsageStats.print(pw);
     }
 
-    private void dumpProto(FileDescriptor fd) {
-        final ProtoOutputStream proto = new ProtoOutputStream(fd);
-        for (UserInfo user : UserManager.get(getContext()).getUsers()) {
-            final int userId = user.getUserHandle().getIdentifier();
-
-            final long userToken = proto.start(FaceServiceDumpProto.USERS);
-
-            proto.write(FaceUserStatsProto.USER_ID, userId);
-            proto.write(FaceUserStatsProto.NUM_FACES,
-                    getBiometricUtils().getBiometricsForUser(getContext(), userId).size());
-
-            // Normal face authentications (e.g. lockscreen)
-            final PerformanceStats normal = mPerformanceMap.get(userId);
-            if (normal != null) {
-                final long countsToken = proto.start(FaceUserStatsProto.NORMAL);
-                proto.write(FaceActionStatsProto.ACCEPT, normal.accept);
-                proto.write(FaceActionStatsProto.REJECT, normal.reject);
-                proto.write(FaceActionStatsProto.ACQUIRE, normal.acquire);
-                proto.write(FaceActionStatsProto.LOCKOUT, normal.lockout);
-                proto.write(FaceActionStatsProto.LOCKOUT_PERMANENT, normal.lockout);
-                proto.end(countsToken);
-            }
-
-            // Statistics about secure face transactions (e.g. to unlock password
-            // storage, make secure purchases, etc.)
-            final PerformanceStats crypto = mCryptoPerformanceMap.get(userId);
-            if (crypto != null) {
-                final long countsToken = proto.start(FaceUserStatsProto.CRYPTO);
-                proto.write(FaceActionStatsProto.ACCEPT, crypto.accept);
-                proto.write(FaceActionStatsProto.REJECT, crypto.reject);
-                proto.write(FaceActionStatsProto.ACQUIRE, crypto.acquire);
-                proto.write(FaceActionStatsProto.LOCKOUT, crypto.lockout);
-                proto.write(FaceActionStatsProto.LOCKOUT_PERMANENT, crypto.lockout);
-                proto.end(countsToken);
-            }
-
-            proto.end(userToken);
-        }
-        proto.flush();
-        mPerformanceMap.clear();
-        mCryptoPerformanceMap.clear();
-    }
-
     private void dumpHal(FileDescriptor fd, String[] args) {
         // WARNING: CDD restricts image data from leaving TEE unencrypted on
         //          production devices: