Move TestForPreservingPMConversions memset to FP file

Fixes CheckGeneratedFiles error introduced by:
    https://skia-review.googlesource.com/c/skia/+/124350

Change-Id: I2e1314c6fa9e6a938a0c26ae49aa5b9121a7229f
Reviewed-on: https://skia-review.googlesource.com/124640
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed