bitbake: toaster: write variables to toaster.conf

With the resent change in rootfs creation code setVariable
rpc calls don't set variables for bitbake workers anymore.

Writen variables to toaster.conf should solve this issue.

[YOCTO #8910]

(Bitbake rev: d6dfe40320ff6ca420d9f9016b4d1d83d10f1d59)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Elliot Smith <elliot.smith@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/bldcontrol/localhostbecontroller.py

@@ -280,6 +280,13 @@ class LocalhostBEController(BuildEnvironmentController):
         # set up the build environment with the needed layers
         self.setLayers(bitbake, layers, targets)
 
+        # write configuration file
+        filepath = os.path.join(self.be.builddir, "conf/toaster.conf")
+        with open(filepath, 'w') as conf:
+            for var in variables:
+                conf.write('%s="%s"\n' % (var.name, var.value))
+            conf.write('INHERIT+="toaster buildhistory"')
+
         # get the bb server running with the build req id and build env id
         bbctrl = self.getBBController()