This switches Sensors HAL policy to the design which enables us to
conditionally remove unnecessary rules from domains which are clients
of Sensors HAL.

Domains which are clients of Sensors HAL, such as system_server, are
granted rules targeting hal_sensors only when the Sensors HAL runs in
passthrough mode (i.e., inside the client's process). When the HAL
runs in binderized mode (i.e., in another process/domain, with clients
talking to the HAL over HwBinder IPC), rules targeting hal_sensors are
not granted to client domains.

Domains which offer a binderized implementation of Sensors HAL, such
as hal_sensors_default domain, are always granted rules targeting
hal_sensors.

P. S. This commit also removes
  allow system_server sensors_device:chr_file rw_file_perms
because this is device-specific and thus not needed in device-agnostic
policy. The device-specific policy of the affected devices already has
this rule.

Test: Device boots, no new denials
Test: adb shell dumpsys sensorservice
      lists tons of sensors
Test: Proprietary sensors test app indicates that there are sensors
      and that the app can register to listen for updates for sensors
      and that such updates arrive to the app.
Bug: 34170079
Change-Id: I61bf779070eabcb64ae73724d62b6e837319a668

Allow sensor HALs to access ashmem memory. This is needed to support
direct delivery of sensor samples to applications.

Test: CTS test for SensorsDirectMode pass.
Change-Id: I00e3c0a0e59d72f84ff48098ddf868c94695d616

All hals need to use hwbinder.

Test: no additional denials
Bug: 34180936
Change-Id: Ie92cdbd79fc75062c4afa4cda53cb57ccde7e370

Adding sepoilcy for sensors.

Test: Sensors work.
Change-Id: Ibbf0c1a22654a17b1573e3761ea9ccd816150255