[LI-HOTFIX] Preallocate maps with exact size instead of the default(w…

…hich is 16) (apache#50) (apache#270)

LI_DESCRIPTION =
EXIT_CRITERIA =

(cherry picked from commit d2f66fa)

Co-authored-by: Virupaksha Swamy Uttanur Matada <viswamy@linkedin.com>

clients/src/main/java/org/apache/kafka/common/protocol/types/Schema.java

@@ -55,7 +55,7 @@ public Schema(Field... fs) {
      */
     public Schema(boolean tolerateMissingFieldsWithDefaults, Field... fs) {
         this.fields = new BoundField[fs.length];
-        this.fieldsByName = new HashMap<>();
+        this.fieldsByName = new HashMap<>(fs.length);
         this.tolerateMissingFieldsWithDefaults = tolerateMissingFieldsWithDefaults;
         for (int i = 0; i < this.fields.length; i++) {
             Field def = fs[i];