ANDROID: GKI: Add write_pending and max_writes fields to swap_info_struct

This is required to resolve ABI diff in swap_info_struct struct.

Bug: 151955270
Test: build and boot without original sysfs files
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
[swatsrid@codeaurora.org: Fix trivial merge conflicts]
Signed-off-by: Swathi Sridhar <swatsrid@codeaurora.org>
(cherry picked from commit ac4b2c42c81b39bc5602b8201d0e998b455391e7)
[surenb: commit amended to include only swap_info_struct changes]
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: Idd145757b12821030bb371b494a41d316ff56d0c