Support renaming fields in renameVariable

RELNOTES: N/A

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=239858177

Author: cushon

check_api/src/main/java/com/google/errorprone/fixes/SuggestedFixes.java

@@ -447,6 +447,17 @@ public void visitIdent(JCTree.JCIdent tree) {
                   fix.replace(tree, replacement);
                 }
               }
+
+              @Override
+              public void visitSelect(JCTree.JCFieldAccess tree) {
+                if (sym.equals(getSymbol(tree))) {
+                  fix.replace(
+                      state.getEndPosition(tree.getExpression()),
+                      state.getEndPosition(tree),
+                      "." + replacement);
+                }
+                super.visitSelect(tree);
+              }
             });
     return fix.build();
   }