Add check for Java VM in Android's SysInfo::IsLowEndDevice()

Android's SysInfo::IsLowEndDevice() calls into Java SysUtils
and thus expects to have a Java VM setup. However when using
command buffer as a standalone library VM doesn't exist.

BUG=skia:2992

Review URL: https://codereview.chromium.org/1769503002

Cr-Commit-Position: refs/heads/master@{#386343}
1 file changed