Fix enum switch warnings

hardware/libhardware/include was being included with -isystem, which
hides warnings.  -Wswitch requires that all cases in a switch statement
on an enum be enum values.  For enums being used as bit flags, cast the
enum to an int.

Bug: 32018017
Test: m -j
Change-Id: Idb430c451d017bb7ec61a7119d6abd87b6dcdc87
1 file changed