Anti aliasing does not work on Android devices when the "8x Multi Sampling" anti aliasing option is selected in the quality settings in Unity editor. It works in the editor's play mode and in standalone builds, however it does not work on Android devices. This is a regression since Unity 4.3.

Reproduced on:
Samsung Galaxy Note 10.1 (GT-N8000) with Android 4.0.4

Reproduced with:
Unity Version 4.3.0f4 (e01000627d60)
Unity Version 4.3.2f1 (0517a5ae8669)

Not reproducible with:
Unity Version 4.2.2f1 (54f0fc09defb)

Resolution:
This issue is device specific. This particular device/gpu mali 400 doesn't support anti aliasing when using a 24bit frame buffer. As of Unity 4.3 we use a non-alpha enabled frame buffer by default since the android hw compositor has problems handling direct frame buffers with alpha.