Description of problem:
Performing a syncable complete export of Content View breaks continuity of importable incremental exports

Version-Release number of selected component (if applicable):
Satellite 6.12

How reproducible:
always

Steps to Reproduce:
1. Create an export organization (or use default) and add some content
2. Create a ContentView, publish new version and perform a complete version export
hammer content-export complete version --organization ExportOrg --content-view TestView --version 1.0
3. Publish new ContentView version and perform a complete syncable version export
hammer content-export complete version --organization ExportOrg --content-view TestView --version 2.0 --format syncable
4. Publish new ContentView version and perform an incremental version export
hammer content-export incremental version --organization ExportOrg --content-view TestView --version 3.0
5. Create an import organization
6. Copy exported content into pulp import directory (cp -R /var/lib/pulp/exports/ExportOrg/TestView /var/lib/pulp/imports/, chown -R pulp:pulp /var/lib/pulp/imports/TestView/)
7. Import complete ContentView version 1.0
hammer content-import version --organization "ImportOrg" --path /var/lib/pulp/imports/TestView/1.0/...
8. Attempt to import version 3.0
hammer content-import version --organization "ImportOrg" --path /var/lib/pulp/imports/TestView/3.0/...

Actual results:
  Could not import the archive.:
    Prior Content View Version specified in the metadata - 'TestView 2.0' does not exist. Please import the metadata for 'TestView 2.0' before importing 'TestView 3.0'

Expected results:
Version 3.0 is imported (just as if no export of 2.0 was done).
Performing a syncable export should not break continuity of importable incremental exports.

Additional info:
Similar issue with repository and library export was resolved in bz 2118431