ASACORE-1173: update AllJoynUnityPackage README

Change-Id: Iee7553c6856c80c25061cf4cebbf762712d78302
Signed-off-by: Tony Wallace <awallace@qce.qualcomm.com>
Merge "ASACORE-1173: update AllJoynUnityPackage README" into RB14.12