Make the method for finding out if a device is org-owned public.

Make isOrganizationOwnedDeviceWithManagedProfile a public method, as
there is no reason to keep this information hidden from apps.

Test: atest CtsDevicePolicyManagerTestCases:com.android.cts.devicepolicy.OrgOwnedProfileOwnerTest#testIsDeviceOrganizationOwnedWithManagedProfile
Test: atest CtsDevicePolicyManagerTestCases:com.android.cts.devicepolicy.MixedProfileOwnerTest#testIsDeviceOrganizationOwnedWithManagedProfile
Test: atest CtsDevicePolicyManagerTestCases:com.android.cts.devicepolicy.MixedDeviceOwnerTest#testIsDeviceOrganizationOwnedWithManagedProfile
Bug: 143518237
Bug: 144978467
Bug: 147340575
Bug: 146123237
Change-Id: Iab45f20c9150a6b8bd48eea610484f36f199d3d7