Bluetooth: bluetooth.le API fixes

Fix minor spelling problems.
Throw IllegalStateException instead of IllegalArgumentException in
build().

Bug: 37532634
Test: none
Change-Id: I73b6f04aec98f5baffb06a363e2a3f71e8cec3c4
(cherry picked from commit 9d4abb5631c7719de8d919e0c37c9aee54354266)