I want to change my android device's Bluetooth UUID to a predefined value so that my BLE beacon can recognize it without pairing with it.
From this question I gathered that I'll have to change the service UUID but I can't find the relevant documents or tutorials.
How can I achieve this change of UUID via my app?
Have you looked at the Android API documentation?
You use this https://developer.android.com/reference/android/bluetooth/le/AdvertiseData.Builder#addServiceUuid(android.os.ParcelUuid) function to set a custom service uuid to be advertised.
A general tutorial for advertising can be found here: https://source.android.com/devices/bluetooth/ble_advertising.