android: Don't allow editing for read-only docs

Previously when experimental mode was enabled in Android
Viewer, a "This file is read-only, saving is disabled."
info was shown to the user when opening a file read-only,
e.g. when the file was passed from a third-party app.

However, editing the document was still possible, a
dialog asking whether or not to save the modified doc
was shown when existing and only then saving would fail.
Disable editing completely for this case, rather than
having the user lose changes in the end.

Change-Id: Ie523971949d11909223aeac4f99023ecf28cb56c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112693
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
diff --git a/android/source/src/java/org/libreoffice/LOKitShell.java b/android/source/src/java/org/libreoffice/LOKitShell.java
index c69e026..46ca256 100644
--- a/android/source/src/java/org/libreoffice/LOKitShell.java
+++ b/android/source/src/java/org/libreoffice/LOKitShell.java
@@ -61,7 +61,7 @@ public class LOKitShell {
    }

    public static boolean isEditingEnabled() {
        return LibreOfficeMainActivity.isExperimentalMode();
        return !LibreOfficeMainActivity.isReadOnlyMode();
    }

    // EVENTS