Yes, UV light is effective in killing all the viral and bacterial cells. And it is believed that UV-C will be effective in disinfecting SARS-CoV2 which is responsible for Covid 19, as earlier it is reported that UV-C disinfection can degrade viruses which are similar to SARS-CoV2 virus (like SARS-CoV1 and MARS-CoV).
But, the effectiveness of UV disinfection is dependent upon exposure time and intensity. So, sunlight could not disinfect the gas pump handles which are not directly exposed to sunlight. Effect of heat due to sunlight is another factor which may be responsible to inhibit virus growth.