Preserve container configuration in rootfs exports and import

[Goldzxcbug]

Problem

Exported rootfs archives did not include the container's current host-side configuration. When users imported an archive, they had to re-enter those settings in the setup wizard.

Changes

• Include the container's current container.config as the first member of exported rootfs archives.
• Read optional root-level configuration during import and prefill the setup wizard with those settings.
• Keep hardware access and privileged mode behind their existing confirmation dialogs.
• Keep rootfs validation in the installation path. Environment files are not imported.

UI

The change reuses the existing wizard layout, loading and error screens, and confirmation dialogs.

Verification

• cd Android && ./build.sh — passed on the local anland branch after merging the current main changes.
• Debug APK installed on a OnePlus OPD2413, SoC SM8750P, Android 16, kernel 6.6.89, aarch64.
• Functional export/import and regression flows have not yet been verified.
• Test rootfs: Ubuntu 26 KDE Wayland aarch64, from release v20261009-135022.
• Published SHA-256: 0896a70afc4c47c2bdcb757af924fa8de131c4434d85e0ed5c17e2a79f5f1b79

[Goldzxcbug]

Additional note: I have verified both the rootfs import and export for the Droidspaces builds from the main branch and the anland branch. Detecting the recommended configuration takes less than 1 second.