BLE Device name is hardcoded

[pan-apple]

Problem

BLEManagerImpl.cpp computes device name using FabricState.LocalNodeId(). This was removed (and hardcoded to 0) in #104 for nRF5 and in #125 for EFR32.

Proposed Solution

Identify the correct replacement for LocalNodeId and use that to compute device name.

Code reference:
nRF5 -

connectedhomeip/src/platform/nRF5/BLEManagerImpl.cpp

Lines 251 to 253 in ca9dfc2

	snprintf(devNameBuf, sizeof(devNameBuf), "%s%04" PRIX32,
	CHIP_DEVICE_CONFIG_BLE_DEVICE_NAME_PREFIX,
	(uint32_t)0);

EFR32 -

connectedhomeip/src/platform/EFR32/BLEManagerImpl.cpp

Lines 584 to 585 in ca9dfc2

	snprintf(mDeviceName, sizeof(mDeviceName), "%s%04" PRIX32, CHIP_DEVICE_CONFIG_BLE_DEVICE_NAME_PREFIX,
	(uint32_t)0);