Error:Cause: buildToolsVersion is not specified.

동료가 나에게 한 항목을 던져 주었는데, 처음에는 잘못을 보고하였다.

Error:(6, 0) Gradle DSL method not found: 'google()'
Possible causes:
The project 'CarJniDemo' may be using a version of the Android Gradle plug-in that does not contain the method (e.g. 'testCompile' was added in 1.1.0).
<a href="fixGradleElements">Upgrade plugin to version 2.3.3 and sync projecta>
The project 'CarJniDemo' may be using a version of Gradle that does not contain the method.
<a href="open.wrapper.file">Open Gradle wrapper filea>
The build file may be missing a Gradle plugin.
<a href="apply.gradle.plugin">Apply Gradle plugina>

아래 코드를

allprojects {
    repositories {
        google()
        jcenter()
    }
}

... 로 바꾸다

allprojects {
    repositories {
        maven { url 'https://maven.google.com' }
        jcenter()
    }
}

문제가 잇달아 오다

Error:Cause: buildToolsVersion is not specified.

build.gradle에 buildToolsVersion 없음

buildToolsVersion "26.0.2"

문제 해결