implementation 'com.android.support:appcompat-v7:28.0.0'

All com.android.support libraries must use the exact same version specification (mixing versions can lead to runtime crashes). Found versions 28.0.0, 26.1.0. Examples include com.android.support:animated-vector-drawable:28.0.0 and com.android.support:support-media-compat:26.1.0 less... (Ctrl+F1)
Inspection info:There are some combinations of libraries, or tools and libraries, that are incompatible, or can lead to bugs. One such incompatibility is compiling with a version of the Android support libraries that is not the latest version (or in particular, a version lower than your targetSdkVersion).

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28

    defaultConfig {
        applicationId "com.theaskdev.sitmangalore"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 17
        multiDexEnabled true
        versionName "5.7"
        ndk.abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        signingConfig signingConfigs.release
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    dexOptions {
        javaMaxHeapSize "4g"
    }
    productFlavors {
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.nineoldandroids:library:2.4.0'
    implementation 'com.android.volley:volley:1.1.0'
    implementation 'com.android.support:multidex:1.0.3'
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation "com.android.support:support-compat:28.0.0"
    implementation "com.android.support:support-core-utils:28.0.0"
    implementation 'com.google.firebase:firebase-messaging:17.3.4'
    implementation 'com.google.firebase:firebase-crash:16.2.1'
    implementation 'com.google.firebase:firebase-core:16.0.7'
}


apply plugin: 'com.google.gms.google-services'

buildscript {
    repositories {
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.3.1'
        classpath 'com.google.gms:google-services:4.2.0'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

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