Disable L8 Shrinking for release

Change-Id: Ic918271a1edf5a56e8e8d8d4dd1c2b637d4a1087
diff --git a/src/main/java/com/android/tools/r8/L8Command.java b/src/main/java/com/android/tools/r8/L8Command.java
index d96a5a1..646a96a 100644
--- a/src/main/java/com/android/tools/r8/L8Command.java
+++ b/src/main/java/com/android/tools/r8/L8Command.java
@@ -163,8 +163,8 @@
     }
 
     public boolean isShrinking() {
-      // Answers true if keep rules, even empty, are provided.
-      return !proguardConfigStrings.isEmpty() || !proguardConfigFiles.isEmpty();
+       // Disable for release.
+       return false;
     }
 
     @Override