x/tools/gopls: regtest flakes on android-amd64-emu

[findleyr]

At least 2 regtests are flaking with some regularity on android-amd64-emu: TestWorkspaceDirAccess and TestUnimportedCompletion.

Due to the nature of these failures (they look like races), I don't think we should just ignore them. However, android is a low priority for gopls and they are causing noise on the builders.

I think we should exclude them from -short for now, but follow up.

CC @stamblerre

[gopherbot]

Change https://golang.org/cl/281857 mentions this issue: gopls/internal/regtest: skip regtests on android-amd64-emu

[stamblerre]

Agreed that we should look at these tests ASAP.

[gopherbot]

Change https://golang.org/cl/283052 mentions this issue: internal/lsp/fake: use hash rather than mtime to identify workdir files

[gopherbot]

Change https://golang.org/cl/283053 mentions this issue: internal/lsp/cache: compare file size when invalidating file cache