Avoid protobuf equals (firebase#1920)

Author: Brian Chen

firebase-firestore/src/main/java/com/google/firebase/firestore/model/Values.java

@@ -120,7 +120,7 @@ public static boolean equals(Value left, Value right) {
  private static boolean numberEquals(Value left, Value right) {
  if (left.getValueTypeCase() == Value.ValueTypeCase.INTEGER_VALUE
  && right.getValueTypeCase() == Value.ValueTypeCase.INTEGER_VALUE) {
- return left.equals(right);
+ return left.getIntegerValue() == right.getIntegerValue();
  } else if (left.getValueTypeCase() == Value.ValueTypeCase.DOUBLE_VALUE
  && right.getValueTypeCase() == Value.ValueTypeCase.DOUBLE_VALUE) {
  return Double.doubleToLongBits(left.getDoubleValue())
@@ -157,7 +157,7 @@ private static boolean objectEquals(Value left, Value right) {
 
  for (Map.Entry<String, Value> entry : leftMap.getFieldsMap().entrySet()) {
  Value otherEntry = rightMap.getFieldsMap().get(entry.getKey());
- if (!entry.getValue().equals(otherEntry)) {
+ if (!equals(entry.getValue(), otherEntry)) {
  return false;
  }
  }