Adb installation error: INSTALL_FAILED_OLDER_SDK

Your connected android device (with old android version) must be comply with the minSdkVersion & targetSdkVersion in build.gradle which is under your module. If not, just to modify them in the build.gradle to align with your android OS version.

But compile & build version could be different, that is ok.

android {
    compileSdkVersion 24
    buildToolsVersion '24.0.3'
    defaultConfig {
        applicationId "xxx.xxx.xxx"
        minSdkVersion 19
        targetSdkVersion 19
        versionCode 1
        versionName "1.0"