usb: android: Skip the work when set_config arrives with same value twice

Some USB hosts may send SET_CONFIGURATION with same value twice.
The current code implementation processing the 2nd set_config and
schedules the work. The android_work() issues disconnect event to
userspace if SetConfiguration with non-zero value is sent twice.
The userspace applications may disconnect the USB and the device
doesn't connect to the host.

Fix this by avoiding the android_work for the second time SET_CONFIGURATION
request when it receives SetConfiguration request with same configuration
value twice from the host.

CRs-Fixed: 661220
Change-Id: Ic450315a9067b9b679b4936480d125e4e4b7cdf7
Signed-off-by: ChandanaKishori Chiluveru <cchilu@codeaurora.org>