Increase the temp-allowlist duration in tests

It is possible there is a delay in app getting to
the background state and then initiating network
activity. We need the app to stay in the
temp allowlist until then.

Fixes: 227418169
Test: atest tests/cts/hostside/src/com/android/cts/net/HostsideRestrictBackgroundNetworkTests.java
Change-Id: I6a98cc17a40cfb54bf3e12f51b5584159e69be0c
1 file changed