Photoshop imports image sequences to make GIF animations

1. Export image sequence from AE

2. Open ps, select[File]->[Script]->[Load a file into a stack...]

3. Import the file or folder and wait until the layers are loaded.

4. Open[Window]->[Timeline]Enable the Timeline panel. I use CS6. If the old version does not have a [timeline], check whether there is a timeline.[Animation]

5. Click the extended menu button in the upper-right corner of the Timeline panel and select[Create a frame from a layer]

6. Play back in the lower corner. If it is reverse playback, select the extended menu[Reverse frame]

7. Select[File]->[Storage format for Web and device...], Select the GIF format from the drop-down list in the upper-right corner, and click[Storage]

Material Design:

Photoshop imports image sequences to make GIF animations