iOS SDK 2.6.3

Bugfixes:
• [LP-10948] Potential fix for pause crash (#328)
• Fix the old cached data based check (#327)
• [LP-11004] Fixing not hiding rich interstitial (#326)
• Fixing a potential crash (#319)

Features:
• [LP-10929] Using operation queue to execute writes in bg (#324)
• Enabling use of TLS (#323)
• E2-1227 Excluding database from iCloud/iTunes sync (#325)