Bump up CameraX version to 1.2.0-alpha01
Bump up CameraX version to 1.2.0-alpha01

Test: ./gradlew camera:camera-[camera2|core|lifecycle|video|extensions|view]:updateApi
Change-Id: Ib8dbf0dd67384866d7ee35c7a980b0de214f67ac

AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,androidx/androidx,androidx/androidx