docs: corrected grammar mistake in Class Overview

 * <p>Note that since streams can be stopped due to resource constraints, the

 * streamID is a reference to a particular instance of a stream. If the stream

 * is stopped to allow a higher priority stream to play, the stream is no

 * longer be valid. However, the application is allowed to call methods on

 * longer valid. However, the application is allowed to call methods on

 * the streamID without error. This may help simplify program logic since

 * the application need not concern itself with the stream lifecycle.</p>

 *