ExternalGraphicsProfiler.h exposes 392 profiler markers to release players without kAvailabilityNonDevelopment flag set

While looking at the profiler stats enumeration issue discovered by user (see https://fogbugz.unity3d.com/f/cases/1376913/) I've found that Apple platforms overrides PROFILER_MARKER globally with PROFILER_MARKER_MASTER pulling the PlatformProfiler.h define in ExternalGraphicsProfiler.h.

That creates few tech debt issues:
1. Profiler markers on OSX/iOS becomes semi-randomly release markers depending on build order and manifest a bug mentioned by a user.
2. The behavior is inconsistent with other platforms where we expose release mode markers explicitly and with documentation.

How to repro:
1. Enable Markers_HaveValidFlagsInDevAndReleasePlayers_OSX test from ProfilerEditorTests (Modules/Profiler/Editor/Tests)
2. Run Markers_HaveValidFlagsInDevAndReleasePlayers_OSX test from ProfilerEditorTests.

Actual Result: Test fails. Error is thrown - e.g. "Marker XR.BlitDepth has 'AvailabilityNonDevelopment' in Non Development Player, but 'Default' in Development Player! Please keep those consistent". Flags of XR.BlitDepth do not match between dev and release players.
Expected Result: Test succeeds