How to reproduce:
1. Open the attached project and "Repro" scene
2. Open Animation window and select Cube in Hierarchy
3. Select some frame in the Animation timeline (0:25) for example, observe that Preview mode is automatically enabled
4. Right click on Transform component of the Cube (on "Transform" title) and select Copy Component
5. Disable Preview mode, right click on Transform component of the Cube and select Paste Component Values

Expected result - Values that were copied during Animation Preview are pasted
Actual result - Values that were copied during Animation Preview are not pasted

Regression introduced in - 2017.1.0a1
Reproducible with - 2017.3.0a7, 2017.2.0b11, 2017.1.1p2, 2017.1.0a1
Not reproducible with - 5.6.3p3

Note - In the earlier 2017.1 versions, Record is enabled when previewing Animations (is automatically enabled), and Preview button is not added yet. To reproduce, just disable Record button instead