feat(sdk-coin-avaxp): use passed delegationFeeRate

instead of the hard coded 2 percent fee

SC-4226

TICKET: SC-4226

Author: noel-bitgo

modules/sdk-coin-avaxp/src/lib/permissionlessValidatorTxBuilder.ts

@@ -526,7 +526,7 @@ export class PermissionlessValidatorTxBuilder extends TransactionBuilder {
 
     // Shares 10,000 times percentage of reward taken from delegators
     // https://docs.avax.network/reference/avalanchego/p-chain/txn-format#unsigned-add-validator-tx
-    const shares = new Int(1e4 * 2);
+    const shares = new Int(1e4 * this._delegationFeeRate);
 
     const addressMaps = [...this.transaction._fromAddresses]
       .sort((a, b) => avaxUtils.bytesCompare(a, b))