[api] Fix estimation error for too little funds
[api] Fix estimation error for too little funds

Right now simulation with too little gas will put your max gas amount
below the min gas units, which will cause it to error with
MAX_GAS_UNITS_BELOW_MIN_TRANSACTION_GAS_UNITS.  Now this fixes, it to
INSUFFICIENT_BALANCE_FOR_TRANSACTION_FEE which makes more sense if
you don't have enough money

aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core