USB: android: Fix missing USB DISCONNECT uevent

Some userspace modules, e.g. MTP, work correctly only if
CONFIGURED uevent is preceded by DISCONNECT uevent. Hence,
explicitly send DISCONNECT uevent if missed out due to
really quick enumeration by USB Host.
Also, wait for some time before sending out CONFIGURED uevent
to give function drivers a chance to wakeup userspace threads
and notify previous disconnect.

Change-Id: I231b8de60b25a05e2316074b8694c9cbc15bb556
CRs-Fixed: 348066
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>