Make doclava treat lint warnings as errors again

This was turned off because of a large number of existing issues. These
have now been baselined or fixed, so reenable the error.

Bug: 217734059
Test: m docs
Change-Id: Ic4947568c125630e8a462a0d175cb1010228ff8c
diff --git a/src/com/google/doclava/Doclava.java b/src/com/google/doclava/Doclava.java
index 5ab2b65..0f7ab3b 100644
--- a/src/com/google/doclava/Doclava.java
+++ b/src/com/google/doclava/Doclava.java
@@ -543,8 +543,7 @@
                     @Override public List<String> getNames() { return names; }
                     @Override public String       getParameters() { return ""; }
                     @Override public boolean      process(String opt, List<String> arguments) {
-                        // b/270335653: disable lint warnings as errors until new findings are addressed.
-                        // Errors.setLintsAreErrors(true);
+                        Errors.setLintsAreErrors(true);
                         return true;
                     }
                 }