SettingsPreferenceFragment has this already set so that the drawer
layout will work when the menu doesn't exist. However, some fragments
are not preference fragments, and we need to set setHasOptionsMenu
manually.
bug:27879503
Change-Id: I6faadeb56dab00af611ac413109800822038c66d
Adds new preference screen for the feature, where the feature can be
enabled/disabled, and delay before click can be specified (implemented
as seek bar preference, enabled iff the feature is enabled).
Preference is added to Accessibility setting. The preference summary is
set to string describing the delay after pointer stops moving before
click is scheduled (the string also contains numerical value of the
delay).
BUG=20049245
Change-Id: Ib7b2f5c24efbd08e3200143c069bcdbc9b5a327a
