Fix some statically detected code issues

This includes: unnecessary semicolons, suppress warnings, switch statements, final/private qualifiers, Optional wrapping, conditionals, both inline and non-inline variables, ternaries, Collection putAll() calls, StringBuilders, and throws declarations.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=244182539

java/google/registry/documentation/FlowDocumentation.java

@@ -113,12 +113,9 @@ public class FlowDocumentation {
   /** Iterates through javadoc tags on the underlying class and calls specific parsing methods. */
   private void parseTags(ClassDoc flowDoc) {
     for (Tag tag : flowDoc.tags()) {
-      switch (tag.name()) {
-        case "@error":
-          parseErrorTag(tag);
-          break;
-        default:
-          // Not a relevant tag.
+      // Everything else is not a relevant tag.
+      if ("@error".equals(tag.name())) {
+        parseErrorTag(tag);
       }
     }
   }