Move resetPasswordTest to pre-O DPC package

DPM.resetPassword is being deprecated in O and only DPC who targets SDK level
below O can still call it. As a result, move the CTS test to its own DPC package

Also try to clear device lockscreen password in tearDown() in case test fails.

Bug: 35417075
Test: cts-tradefed run cts-dev -m CtsDevicePolicyManagerTestCases -t com.android.cts.devicepolicy.MixedProfileOwnerTestApi25
Test: cts-tradefed run cts-dev -m CtsDevicePolicyManagerTestCases -t com.android.cts.devicepolicy.MixedDeviceOwnerTestApi25
Test: cts-tradefed run cts-dev -m CtsDevicePolicyManagerTestCases -t com.android.cts.devicepolicy.MixedManagedProfileOwnerTestApi25
Change-Id: I482f84587dc567410dd6df5e61fe94ec29dadaf5
10 files changed