Fix description for error methods (#770)

Author: sfod

src/main/java/software/amazon/awssdk/crt/CRT.java

@@ -502,7 +502,7 @@ private static native void awsCrtInit(int memoryTracingLevel, boolean debugWait,
     public static native int awsLastError();
 
     /**
-     * Given an integer error code from an internal operation
+     * Given an integer error code from an internal operation, get a corresponding description for it.
      *
      * @param errorCode An error code returned from an exception or other native
      *                  function call
@@ -511,7 +511,7 @@ private static native void awsCrtInit(int memoryTracingLevel, boolean debugWait,
     public static native String awsErrorString(int errorCode);
 
     /**
-     * Given an integer error code from an internal operation
+     * Given an integer error code from an internal operation, get a corresponding string identifier for it.
      *
      * @param errorCode An error code returned from an exception or other native
      *                  function call