[DPM] Allow lower strong auth timeout on debuggable builds

Timeout can be set to lower than 1h on debuggable builds (eng, user-debug)
using persist.sys.min_str_auth_timeo system property. This allows manual
testers to more easily carry out testing scenarios.

Bug: 29825955
Test: manual without setting the property: if timeout is set to less than 1h, it's clamped to 1h
Test: manual with setting the property: on user-debug build with "adb root && adb shell setprop persist.sys.min_str_auth_timeo 30000"
Change-Id: I8cd871e3d04b2c6c7164f684b9a6a24e7292bfab
1 file changed