Add instant cookie APIs

This change adds APIs for instant apps to store cookie data
that is presisted across instant installs and across the
upgrade from an instant to a standard app. Standard apps
can use the cookie APIs but when they are uninstalled the
cookie is also deleted. The cookies are kept longer than
the instant apps as they are much smaller - 16KB by default.
We can change the cookie size via a system setting i.e.
after we ship we can increase size if needed.

We also add internal APIs to surface information about
installed and uninstalled instant apps which should be
used for showing them in the UI. For this puporse we store
the icon, permissions, and label of uninstalled apps. If
the app is re-installed we drop this meta-data but keep
the cookie around. If we have cookie data stored and the
signing cert of the app changes when it gets re-intalled
we wipe the cookie.

Test: CTS tests pass; hiddent APIs tested manually

Change-Id: If145c0440cc61a5303e2cbb70228d235d36037a5