Here is the demo.

Code:

// declare $json
$array=json_decode($json,true);  // decode as array
// overwrite subarray with zero-indexed keys while preserving subarray values
$array['all_counts_reports']=array_values($array['all_counts_reports']);
var_export(json_encode($array));  // return to json

Input:

$json='{  
   "all_counts_reports":{  
      "26":{  
         "name":"kumar",
         "date":"2017-04-27",
         "trips_per_day":"2",
         "cash_trips":"0",
         "credit_trips":"1",
         "compliment_trips":"1"
      },
      "28":{  
         "name":"kumar",
         "date":"2017-04-29",
         "trips_per_day":"1",
         "cash_trips":"1",
         "credit_trips":"0",
         "compliment_trips":"0"
      }
   }
}';

Output:

'{"all_counts_reports":
    [
        {"name":"kumar",
         "date":"2017-04-27",
         "trips_per_day":"2",
         "cash_trips":"0",
         "credit_trips":"1",
         "compliment_trips":"1"
        },
        {"name":"kumar",
         "date":"2017-04-29",
         "trips_per_day":"1",
         "cash_trips":"1",
         "credit_trips":"0",
         "compliment_trips":"0"
        }
    ]
}'

In your javascript, use JSON.parse() to strip the wrapping single quotes:

var str='{"all_counts_reports":[{"name":"kumar","date":"2017-04-27","trips_per_day":"2","cash_trips":"0","credit_trips":"1","compliment_trips":"1"},{"name":"kumar","date":"2017-04-29","trips_per_day":"1","cash_trips":"1","credit_trips":"0","compliment_trips":"0"}]}';
var json=JSON.parse(str);
console.log(json);

And because we are running with assumptions, if you want to remove the all_counts_reports key as well, you can use this one-liner:

Code:

$new_json=json_encode(array_values(current(json_decode($json,true))));

Output:

'[{"name":"kumar","date":"2017-04-27","trips_per_day":"2","cash_trips":"0","credit_trips":"1","compliment_trips":"1"},{"name":"kumar","date":"2017-04-29","trips_per_day":"1","cash_trips":"1","credit_trips":"0","compliment_trips":"0"}]'

$array = json_decode($your_json_string,true);
print_r($array);
$result = array();
foreach($array['all_counts_reports'] as $rep){
    $result['all_counts_reports'][] = array(
        "name"=>$rep['name'],
        "date"=>$rep['date'],
        "trips_per_day"=>$rep['trips_per_day'],
        "cash_trips"=>$rep['cash_trips'],
        "credit_trips"=>$rep['credit_trips'],
        "compliment_trips"=>$rep['compliment_trips'], 
    );
}

$result_json = json_encode($result);
echo $result_json;

There may be better solution, but this one is right now in my mind

Its unclear that what you looking for, if you just want to remove and dont want to maintain as original json then you can do like this example. But if you dont want your all_counts_reports treated as array [] then this example will not help.

And simply pass to android then above will work.