[iOS] App always asks Bluetooth permission right on it start

[minhtritc97]

It asks the user for Bluetooth Permissions on App launch, without making any reference to the package methods in the Apps' code
Expected: only ask for bluetooth permission if app call any method from the package.

[hungthinhitj]

the cause of this problem is from the 3rd package name flutter_scan_bluetooth,i fixed it package by moving CBCentralManager initialization to "handle" function in native swift code ( according to pauldemarco/flutter_blue#599 )