Merge "Improve code style in Struct.java and add tests for Type.U64 represented by long primitive." am: 2626b4fd9d am: 46ee93c802 am: ec218fbfd7

Original change: https://android-review.googlesource.com/c/platform/frameworks/libs/net/+/1455947

Change-Id: If93e4daaf095b3f55762a2ad348ca042035cfe68