post_process_props: Write mangled properties back to file instead of stdout
post_process_props: Write mangled properties back to file instead of stdout

Change-Id: I78b642400c46019165f12d409a238344ca6e09dd
Signed-off-by: Mike Lockwood <368d0007e4626f70737d16df5e49ed8806b98c3f@android.com>

xorware/android_build,see4ri/lolili,RR-msm7x30/platform_manifest,xorware/android_build,pranav01/platform_manifest,ND-3500/platform_manifest,hagar006/platform_manifest,fallouttester/platform_manifest,xorware/android_build,Hybrid-Power/startsync,knone1/platform_manifest,xorware/android_build,xorware/android_build