GC: Close File.lines stream

GC: Close File.lines stream

From File#lines javadoc: The returned stream from File Lines
encapsulates a Reader. If timely disposal of file system resources is
required, the try-with-resources construct should be used to ensure
that the stream's close method is
invoked after the stream operations are completed.

Wrap File.lines with try-with-resources.

Change-Id: I82c6faa3ef1083f6c7e964f96e9540b4db18eee8
Signed-off-by: Xing Huang <xingkhuang@google.com>
(cherry picked from commit 172a207945da376b6b4143305aef2af56f7c42e2)