Enforce hard limits on hosts per package and widgets per host.

Bug: 353240784
Test: manually verified with PoC app that at most 20 hosts can exists
Flag: EXEMPT CVE
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:c30c8a6956e275821ca328dcf404c5d63286326b)
Merged-In: I60ee7faf57ed719f93cafad212fef24964dec99f
Change-Id: I60ee7faf57ed719f93cafad212fef24964dec99f
1 file changed