Ensure compatdx and compatproguard proper extensions of R8.

Bug: 132911943
Change-Id: I90c3633b93b8a6214004d67bd520f1a97f5e47b6
diff --git a/src/main/keep-compatdx.txt b/src/main/keep-compatdx.txt
index 75a8012..e4c5688 100644
--- a/src/main/keep-compatdx.txt
+++ b/src/main/keep-compatdx.txt
@@ -2,5 +2,9 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
--keep public class com.android.tools.r8.compatdx.CompatDx { public static void main(java.lang.String[]); }
--keepattributes LineNumberTable
+# This entry must remain a proper extension of R8 to ensure all required parts are kept.
+-include keep.txt
+
+-keep public class com.android.tools.r8.compatdx.CompatDx {
+  public static void main(java.lang.String[]);
+}
diff --git a/src/main/keep-compatproguard.txt b/src/main/keep-compatproguard.txt
index e29d13e..80ca009 100644
--- a/src/main/keep-compatproguard.txt
+++ b/src/main/keep-compatproguard.txt
@@ -2,5 +2,9 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
--keep public class com.android.tools.r8.compatproguard.CompatProguard { public static void main(java.lang.String[]); }
--keepattributes LineNumberTable
+# This entry must remain a proper extension of R8 to ensure all required parts are kept.
+-include keep.txt
+
+-keep public class com.android.tools.r8.compatproguard.CompatProguard {
+  public static void main(java.lang.String[]);
+}