interceptor: generalize environment variable access
Generalize the access to single environment variable values as this is a
commonly used functionality. command_getenv returns an optional to
indicate whether the value had been set at all and hence allows
contextual boolean use, e.g.
if (command_getenv(command, kEnvVariable)) {
// something
}
Bug: 206894758
Signed-off-by: Matthias Maennich <[email protected]>
Change-Id: Icda8d0709b6fe394630729c245a0486fcf718157