2.7.2rc2: Feature improvements and bug fixes

What's Changed

• [2.7] Lower Downloader logging verbosity by @nvidianz in #3913
• [2.7] Cherry pick Convert PSI example to use recipe (#3901) by @YuanTingHsieh in #3911
• [2.7] Redesign Cifar10 PT by @holgerroth in #3905
• [2.7] Restructure CIFAR-10 PT example by @holgerroth in #3916
• [2.7] Refactor CIFAR-10 TensorFlow example by @holgerroth in #3919
• [2.7] Consolidate BaseFedJob and fedavg.py and Fix import error for TBAnalyticsReceiver by @nvkevlu in #3918
• [2.7] Cherry pick from main by @YuanTingHsieh in #3920
• [2.7] Cherry pick of Fix preflight check and ci (#3917) by @YuanTingHsieh in #3929
• [2.7] Fix Job API TF examples by @holgerroth in #3926
• [2.7] Kaplan Meier updates by @ZiyueXu77 in #3935
• [2.7] Multinode doc update by @holgerroth in #3939
• [2.7] Add missing tensorboard requirements by @holgerroth in #3938
• [2.7] Cherry pick cross site eval 3923 by @nvkevlu in #3936
• [2.7] Improve error message in client API by @holgerroth in #3947
• [2.7] Removed references to ws by @nvidianz in #3950
• [2.7] Cherry pick 3930 3945 by @YuanTingHsieh in #3952
• [2.7] Cherry-pick of Consolidate LR examples (#3944) by @YuanTingHsieh in #3953
• [2.7] Expose launch_once option in ScriptRunner by @holgerroth in #3954

Full Changelog: 2.7.2rc1...2.7.2rc2