Move a layer duration bar but not its keyframes

1. Make a note of the time at which the first keyframe appears.
2. In the layer outline, click the name of one or more layer properties containing the keyframes you want to keep at the same times.
3. Choose Edit > Cut.
4. Move or stretch the layer duration bar to its new In and Out points.
5. Move the current-time indicator to the time at which the first keyframe appeared before you cut the keyframes.
6. Choose Edit > Paste.

 community help (adobe.com)