nvs_flash_init may return an error code in some cases, and applications
should check this error code (or at least assert on it being ESP_OK, to
make potential issues more immediately obvious).
This change modifies all the examples which use NVS to check the error
code. Most examples get a simple ESP_ERROR_CHECK assert, while NVS
examples, OTA example, and NVS unit tests get a more verbose check which
may be used in real applications.
1. add new APIs bt controller enable/disab/deinit
2. make bt controller work need to call two APIs of esp_bt_controller_init and enable
3. modify phy init to make mac reset once