Edit metadata for Secure File manager:

- update description
 - remove previous builds

metadata/com.securefilemanager.app.yml

@@ -0,0 +1,23 @@
+Categories:
+  - Security
+  - System
+License: GPL-3.0-or-later
+SourceCode: https://github.com/Secure-File-Manager/Secure-File-Manager
+IssueTracker: https://github.com/Secure-File-Manager/Secure-File-Manager/issues
+Changelog: https://github.com/Secure-File-Manager/Secure-File-Manager/blob/HEAD/CHANGELOG.md
+
+RepoType: git
+Repo: https://github.com/Secure-File-Manager/Secure-File-Manager
+
+Builds:
+  - versionName: 0.1.2-beta2
+    versionCode: 4
+    commit: v0.1.2-beta2
+    subdir: app
+    gradle:
+      - yes
+
+AutoUpdateMode: Version v%v
+UpdateCheckMode: Tags
+CurrentVersion: 0.1.2-beta2
+CurrentVersionCode: 4