Use prebuilt signapk.jar for unbundled branch.
Use prebuilt signapk.jar for unbundled branch.

Change-Id: I762b23931042f7ffde829aaf928f54df46a49d78

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