Make WifiDppEnrolleeActivity launches explicit

Bug: 180518134
Test: make RunSettingsRoboTests \
ROBOTEST_FILTER=WifiDppUtilsTest\|WifiDialogActivityTest
Test: Manually verified b/180518134 attack is no longer possible

Change-Id: I8c4e1e17117582c78671d0e4658bd87715a9a046
(cherry picked from commit 59c0a7bc634a8f3bd205b2c444330af18ab0d0ff)
7 files changed