Verification builds:
1.2.0.7 Retail

Summary:
Since 0.15.x, redstone and components could be placed on glass, which was confirmed as a PE exclusive feature. However, this behaviour is missing for stained glass added in the 1.2.x beta.

Steps to Reproduce:

1. Place some stained glass
2. Place redstone dust on the stained glass

Observed Results:
It's not possible to place redstone items on the stained glass.

Expected Results:
Logically, it should behave in the same way as regular glass.

Screenshots/Videos attached: Yes

Notes:
Please see ticket MCPE-16872 for intended behaviour for glass.