I know that this question is marked an "answered" - but the reality is that the answer was not correct in my case and I want to share.
I initially came to the conclusion that the most accurate answer above was from QueyJoh - "this is something handled by iOS ... Short answer: it's out of your hands."
However after experimenting I managed to locate the issue as being entries in my info.plist file controlling the status bar. Specifically I had entries for "UIStatusBarHidden" and "UIStatusBarStyle".
Removing these entries from my plist file immediately stopped my app from showing the Splash screen when switching away from my app and back again.
Problem solved.
Matthew
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…