China has no permanent friends and foes like in Politics!
Once they were very close to US during cold war but after that they became economic hub of the world due to sheer economies of scale and political culture . Very hard or impossible to beat. Now close to Russia . China is unpredictable if you consider their voting in past. But they have so far backed SL when we needed .
We have to understand if china bail us out lot of other debtors will also default and ask for same concessions.
I do not blame china it is MR who got their Exim Bank loans and commecial loans on terms heavily favour them at high rates (considering other lending institutions such as WB, ADB, JAICA , CDF, etc) . So what china ask us is to honour loan obligations! If not we can sell some assets to them! But this is not in terms of loan agreement, but to keep them in good books eg Hambantota Harbour we spend nearly 2Biliion and gave it for 1 billion and 99 year lease !!