How to tell Gradle to use a different AndroidManif

I have a multi-module project. From the root of my project (which contains multiple modules), I want to be able to call 'gradle build' and have it use a different AndroidManifest in one of my modules depending on some parameter I pass in. What's the best way to accomplish this? Should I use a gradle.properties file or can I specify a different build.gradle somehow in my settings.gradle file? Any help appreciated!

settings.gradle:

include 'ActionBarSherlock'
include '<main_app>'

build.gradle:

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:0.4.2'
    }
}

apply plugin: 'android'

dependencies {
    compile project(':ActionBarSherlock')
}

android {
    buildToolsVersion "17.0"
    compileSdkVersion 17

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
        }
    }
}

I'm looking for the best way to use a different AndroidManifest.xml, say one I have in //test/AndroidManifest.xml. And I need to be able to specify this change from the command-line. Any ideas?

I solved this by using different build types.

Here's my build.gradle:

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:0.4.2'
   }
}

apply plugin: 'android'

dependencies {
    compile project(':facebook-android-sdk-3.0.1:facebook')
    compile project(':google-play-services_lib')
    compile project(':nineoldandroids')
    compile project(':SlidingMenu-master:library')
    compile project(':ViewPagerIndicator')
    compile project(':volley')
    compile project(':windowed-seek-bar')
    compile files('compile-libs/androidannotations-2.7.1.jar', 'libs/Flurry_3.2.1.jar', 'libs/google-play-services.jar', 'libs/gson-2.2.4.jar', 'libs/picasso-1.1.1.jar', 'libs/crittercism_v3_0_11_sdkonly.jar', 'libs/gcm.jar', 'libs/apphance-library.jar')
}

android {
    buildToolsVersion "17.0"
    compileSdkVersion 17

    signingConfigs {
        debug {
            storeFile file('keystores/debug.keystore')
        }
    }

    buildTypes {
        debug {
            sourceSets {
                main {
                    manifest.srcFile 'AndroidManifest.xml'
                    java.srcDirs = ['src']
                    resources.srcDirs = ['src']
                    aidl.srcDirs = ['src']
                    renderscript.srcDirs = ['src']
                    res.srcDirs = ['res']
                    assets.srcDirs = ['assets']
                }
            }
        }

        release {
            zipAlign true
            sourceSets {
                main {
                    manifest.srcFile 'AndroidManifest.xml'
                    java.srcDirs = ['src']
                    resources.srcDirs = ['src']
                    aidl.srcDirs = ['src']
                    renderscript.srcDirs = ['src']
                    res.srcDirs = ['res']
                    assets.srcDirs = ['assets']
                }
            }
        }

        utest {
            debuggable true
            signingConfig signingConfigs.debug

            sourceSets {
                main {
                    manifest.srcFile 'utest/AndroidManifest.xml'
                    java.srcDirs = ['src']
                    resources.srcDirs = ['src']
                    aidl.srcDirs = ['src']
                    renderscript.srcDirs = ['src']
                    res.srcDirs = ['res']
                    assets.srcDirs = ['assets']
                }
            }
        }
    }
}

You can see that for my utest build, I'm specifying a manifest in a different directory. works.