Cannot add task 'wrapper' as a task with that name already exists

You can also update

task wrapper(type: Wrapper) {    gradleVersion = '4.4'        distributionUrl = distributionUrl.replace("bin", "all")}

to

wrapper {    gradleVersion = '4.4'    distributionUrl = distributionUrl.replace("bin", "all")}

As

Overriding built-in tasks deprecated in 4.8 now produces an error.

Attempting to replace a built-in task will produce an error similar to the following:

Cannot add task 'wrapper' as a task with that name already exists.

see the last paragraph of Tasks & properties:https://docs.gradle.org/5.2.1/userguide/upgrading_version_4.html

and Customizing the Wrapper task:https://docs.gradle.org/5.2.1/userguide/gradle_wrapper.html#customizing_wrapper

which version of gradle do you use in your environment?

If you use gradle version 5.x you have to modify 「task wrapper」 as below.

task wrapper(type: Wrapper) {    gradleVersion = '4.4'    distributionUrl = distributionUrl.replace("bin", "all")}

↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓

wrapper {    gradleVersion = '4.4'    distributionUrl = distributionUrl.replace("bin", "all")}

if "gradle-wrapper.properties" file already have these codes

distributionBase=GRADLE_USER_HOMEdistributionPath=wrapper/distszipStoreBase=GRADLE_USER_HOMEzipStorePath=wrapper/distsdistributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip

then you can remove

task wrapper(type: Wrapper) {    gradleVersion = '4.4'    distributionUrl = distributionUrl.replace("bin", "all")}

from build.gradle