Revert of Skia recipe: Use [depot_tools]/gsutil.py instead of [depot_tools]/third_par...

Revert of Skia recipe: Use [depot_tools]/gsutil.py instead of [depot_tools]/third_party/gsutil/gsutil (patchset #1 id:1 of https://codereview.chromium.org/2298293002/ )

Reason for revert:
Broke all nanobench uploads, eg. https://uberchromegw.corp.google.com/i/client.skia.android/builders/Perf-Android-Clang-Nexus6p-CPU-Snapdragon810-arm64-Release-GN_Android/builds/154/steps/Upload%20perf%20results/logs/stdio

Original issue's description:
> Skia recipe: Use [depot_tools]/gsutil.py instead of [depot_tools]/third_party/gsutil/gsutil
>
> The latter is being removed in https://codereview.chromium.org/2280023003/
> Is also pinned to 3.25, whereas the former is updated more often.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2298293002
>
> Committed: https://skia.googlesource.com/skia/+/f15590f803596f51d0950994b2aeb623d2d1fc24

TBR=hinoka@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review-Url: https://codereview.chromium.org/2355943002