metadata: Make ArchivePolicy an interger internally

tests/metadata-rewrite-yml/app.with.special.build.params.yml

@@ -95,7 +95,7 @@ Builds:
     versionCode: 51
     disable: Labelled as pre-release, so skipped
 
-ArchivePolicy: 0 versions
+ArchivePolicy: 0
 AutoUpdateMode: None
 UpdateCheckMode: None
 CurrentVersion: 2.1.2

tests/metadata-rewrite-yml/org.fdroid.fdroid.yml

@@ -944,7 +944,7 @@ Builds:
     gradle:
       - yes
 
-ArchivePolicy: 12 versions
+ArchivePolicy: 12
 AutoUpdateMode: None
 UpdateCheckMode: Static
 CurrentVersion: 0.102.3

tests/metadata.TestCase

@@ -1866,7 +1866,7 @@ class MetadataTest(unittest.TestCase):
                       - NonFreeAssets
                       - UpstreamNonFree
 
-                ArchivePolicy: 4 versions
+                ArchivePolicy: 4
                 AutoUpdateMode: Version v%v
                 UpdateCheckMode: Tags
                 CurrentVersion: '1.5'

tests/metadata/app.with.special.build.params.yml

@@ -94,7 +94,7 @@ Builds:
     versionCode: 51
     disable: Labelled as pre-release, so skipped
 
-ArchivePolicy: 0 versions
+ArchivePolicy: 0
 AutoUpdateMode: None
 UpdateCheckMode: None
 CurrentVersion: 2.1.2

tests/metadata/dump/app.with.special.build.params.yaml

@@ -1,7 +1,7 @@
 AllowedAPKSigningKeys: []
 AntiFeatures:
   UpstreamNonFree: {}
-ArchivePolicy: 0 versions
+ArchivePolicy: 0
 AuthorEmail: null
 AuthorName: null
 AuthorWebSite: null

tests/metadata/dump/com.politedroid.yaml

@@ -3,7 +3,7 @@ AntiFeatures:
   NoSourceSince:
     en-US: '1.5'
   NonFreeNet: {}
-ArchivePolicy: 4 versions
+ArchivePolicy: 4
 AuthorEmail: null
 AuthorName: null
 AuthorWebSite: null

tests/metadata/dump/org.videolan.vlc.yaml

@@ -1,6 +1,6 @@
 AllowedAPKSigningKeys: []
 AntiFeatures: {}
-ArchivePolicy: 9 versions
+ArchivePolicy: 9
 AuthorEmail: null
 AuthorName: null
 AuthorWebSite: null

tests/update.TestCase

@@ -1411,7 +1411,7 @@ class UpdateTest(unittest.TestCase):
                 self.assertDictEqual(
                     metadata_content,
                     {
-                        'ArchivePolicy': '',
+                        'ArchivePolicy': None,
                         'AuthorEmail': '',
                         'AuthorName': '',
                         'AuthorWebSite': '',