[Wi-Fi HAL Device Manager] Status callback semantics change

Change behavior of status callback/API:
- Listener provides a status change only (onStatusChange)
  - Triggered when Wi-Fi is started or stopped
  - Triggered when Wi-Fi HAL service dies or restarts
- API for
  - isStarted(): indicates if Wi-Fi is started or stopped
  - isReady(): indicates if Wi-Fi HAL service is alive

Bug: 34474043
Test: unit tests
Change-Id: I8babb00ea8a2c8c485d1661255644434f0787d8e
4 files changed
tree: 9d3cea1360e82d3e1c0bb1da45a3c0f2558f6260
  1. libwifi_hal/
  2. libwifi_system/
  3. service/
  4. tests/
  5. PREUPLOAD.cfg