v21.12 service pack 4

The usual service pack discussion issue, suggestions welcome.

• upgrade postmarketos-tweaks
• upgrade Linux ODROID-HC2 5.16.14
• add samsung-espress3g
• upgrade n900 kernel (!3032 (merged))
• bump lima timeout (assuming related MR !3050 (closed) gets merged soon and this sees at least a few days of testing in edge; this is the relevant patch: #805 (comment 907266635))

ETA: calendar week 15