CEC: Do null/empty check against the parameter for checkRecordSource()

This prevents out-of-bound exception from occurring.

Bug: 19188370
Change-Id: I051dccf7760cb542ea3dc9b0adc9625fa2ad8b1f

core/java/android/hardware/hdmi/HdmiRecordSources.java

@@ -759,6 +759,8 @@ public final class HdmiRecordSources {
      */
     @SystemApi
     public static boolean checkRecordSource(byte[] recordSource) {
+        if (recordSource == null || recordSource.length == 0) return false;
+
         int recordSourceType = recordSource[0];
         int extraDataSize = recordSource.length - 1;
         switch (recordSourceType) {