Revert of Hack around broken snapshot generation in the GN build on Android....

Revert of Hack around broken snapshot generation in the GN build on Android. (patchset #1 id:1 of https://codereview.chromium.org/832413005/)

Reason for revert:
Suspected to block the current v8 roll:
https://codereview.chromium.org/842783003/

Original issue's description:
> Hack around broken snapshot generation in the GN build on Android.
>
> The generated snapshot just crashes on the device, but
> disabling snapshots allows us to run V8 just fine which
> is sufficient for our purposes at this point.
>
> Mojo/Sky are GN-only so we depend on the V8 GN build even if
> it's not considered production for Chromium yet.
>
> R=jochen@chromium.org
>
> Committed: https://crrev.com/3e97df1ee8b8bfdddd63ad3c7b79960d24c83b74
> Cr-Commit-Position: refs/heads/master@{#25982}

TBR=jochen@chromium.org,eseidel@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/841043002

Cr-Commit-Position: refs/heads/master@{#25991}

BUILD.gn

@@ -17,8 +17,7 @@ v8_enable_verify_heap = false
 v8_interpreted_regexp = false
 v8_object_print = false
 v8_postmortem_support = false
-# TODO(eseidel): The snapshot generated by the GN Android build crashes.
-v8_use_snapshot = !is_android
+v8_use_snapshot = true
 v8_enable_extra_checks = is_debug
 v8_target_arch = cpu_arch
 v8_random_seed = "314159265"