Added UE Start/End comments around every UE modification for easier merge sanity checking in the future.
#rb Lukas.Hermanns
[CL 15864925 by Ryan Vance in ue5-main branch]
#rnx
#rb none
#ROBOMERGE-SOURCE: CL 10869250 via CL 10869537 via CL 10869906
#ROBOMERGE-BOT: (v613-10869866)
[CL 10870965 by ryan durand in Main branch]
If you still need to old behavior of searching for a library we use the new PublicSystemLibraries instead (used very sparingly).
Also updated conventions on importing Android libraries to use the newly introduced Android Architecture instead, which is always set to a valid architecuture (unlike Target.Architecture for the general case)
Lastly I updated some build.cs files that were doing filesystem enumeration or copying as they were being parsed, this is highly discouraged (partially because we cache filesystem operations but also it adds a cost to something we expect to be very fast). Any operations like this should be done as part of the build if they have to be done at all.
#rb none
[CL 7918851 by Joakim Lindqvist in Dev-Build branch]
