USB: android: set use_os_string with android composite device

use_os_string of composite device is used with f_fs driver to make
decision about allocating extended compat os descriptors related
memory. If use_os_string is not set and adbd is passing extended
compat descriptors, unhandled page fault related crash is seen
when extended compat os descriptor is being copied using memcpy.
Fix this issue by setting use_os_string flag to true with android
composite device which makes sure to allocate memory for extended
compat os descriptor with f_fs driver.

CRs-Fixed: 994161
Change-Id: Ie8fa7e111a35a95423456583e6da0a469126e085
Signed-off-by: Mayank Rana <mrana@codeaurora.org>