Update K-9 Mail to 5.700 (27000)

This is a pre-release.

metadata/com.fsck.k9.yml

@@ -464,6 +464,16 @@ Builds:
     rm:
       - tools/android-studio/settings.jar
 
+  - versionName: '5.700'
+    versionCode: 27000
+    commit: '5.700'
+    subdir: app/k9mail
+    gradle:
+      - yes
+    rm:
+      - tools/android-studio/settings.jar
+    prebuild: echo 'org.gradle.jvmargs=-Xmx1g' >> ../../gradle.properties
+
 AutoUpdateMode: Version %v
 UpdateCheckMode: RepoManifest/5.6-MAINT
 CurrentVersion: '5.600'