Optimize the loop processing of URL decoding

[shane-zfx]

Hey guys, I saw the following content when I was studying the es source code.

elasticsearch/server/src/main/java/org/elasticsearch/rest/RestUtils.java

Lines 148 to 160 in 4a49c08

	private static boolean decodingNeeded(String s, int size, boolean plusAsSpace) {
	boolean decodingNeeded = false;
	for (int i = 0; i < size; i++) {
	final char c = s.charAt(i);
	if (c == '%') {
	i++; // We can skip at least one char, e.g. `%%'.
	decodingNeeded = true;
	} else if (plusAsSpace && c == '+') {
	decodingNeeded = true;
	}
	}
	return decodingNeeded;
	}

I think this method can be optimized in terms of performance efficiency. e.g.

for (int i = 0; i < size; i++) {
    final char c = s.charAt(i);
    if (c == '%' || (plusAsSpace && c == '+')) {
         return true;
    } 
}

If it's necessary，I'll submit a PR later

[elasticsearchmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)