Camera: Prevent simultenous HAL initialization

If camera client fails to initialize then connectHelper just return
error code without explicitly disconnect the client.
This could cause the HAL to be initialized between the conflicting
devies, if multiple camera connect attempt is invoked simultaneously.

This patch will prevent the situation by explicitly disconnecting the
client before returning the error code.

Bug: 290325991
Test: Manual test with the OEM application
Change-Id: I2d7a14c01ed5ae6e0f4335f1f0be5742c637b8ee