recovery: mount with ensure_path_mounted_at()

ensure_path_mounted_at() takes care of the
logical partitions case. This fixes framework-only
OTA, where vendor partition needs to be mounted
to get existing info on the device.

Test: vintf_object_recovery_test
Bug: 118634720
Change-Id: I399cb056330596907bcfafa2e4d4149c244421f9
3 files changed