layer endDate is parsed incorrectly during build

[ZachTRice]

Description

The layer endDate is parsed incorrectly. If you inspect a layer like black marble; 2016-01-01 from GC gets transformed into 2017-01-01T00:00:00Z instead of 2016-01-01T00:00:00Z.

The layer startDate work as intended.

Another example: SWDB_Aerosol_Optical_Thickness_550nm_Monthly

<Value>1997-10-01/2008-01-01/P1M</Value>
<Value>2008-04-01/2008-06-01/P1M</Value>
<Value>2008-08-01/2009-04-01/P1M</Value>
<Value>2009-06-01/2009-08-01/P1M</Value>
<Value>2009-11-01/2010-12-01/P1M</Value>

Expected behavior:
startDate should equal: 1997-10-01T00:00:00Z
endDate should equal: 2010-12-01T00:00:00Z

Actual behavior:
startDate actually equals: 1997-10-01T00:00:00Z (correct)
endDate actually equals: 2011-01-01T00:00:00Z (incorrect)

Note: Looks like end_date = determine_end_date(times[2], end_date) is the likely cause since this bug only affects monthly and yearly layers and we have the following in processTemporalLayer.py:

if times[2] != "P1D":
                    end_date = determine_end_date(times[2], end_date)

determine_end_date does an additional isodate parse

Environment

Version: 2.2.0+
Browser: all