Only enable the libcap dependency on Linux host.

The libcap dependency added by commit 9a187ad18c68b960a4882d4eee49e41c99eb519c
caused build failures on sdk_mac because the dependency is added to
`not_windows`, which includes `darwin`, while libcap is not available on
`darwin`. This CL fixes the issue.

Bug: 239756489
Test: Presubmit
Test: https://android-build.googleplex.com/builds/abtd/run/L82100000955591108
Change-Id: I8358498e777d4680a6150f620e34eed7f0f33271
Merged-In: I8358498e777d4680a6150f620e34eed7f0f33271
(cherry picked from commit 2b2d2872ed4ce1de225d9114772e592ca3e50b75)
1 file changed