Add integration testing infrastructure

Fix mutator registration for tests to allow different tests
in the same package to register different mutators.

Allow tests to track the resulting ModuleBuildParams objects
to use in assertions, and provide helpers for getting them.
For example:
    config := android.TestConfig(buildDir)
    ctx := android.NewTestContext()
    ctx.RegisterModuleType(...)
    ctx.MockFileSystem(...)
    ctx.ParseBlueprintsFile("Android.bp")
    ctx.PrepareBuildActions(config)
    ctx.Register()
    // Get the Inputs value passed to the javac rule for the foo module
    inputs := ctx.ModuleForTests("foo".Rule("javac").Inputs

Test: java_test.go
Change-Id: I10c82967f5f3586d2c176f169906b571ed82fc73

1 files changed, 1 insertions, 0 deletions

diff --git a/Android.bp b/Android.bp
index 496dcd28..250c969e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -51,6 +51,7 @@ bootstrap_go_package {
         "android/paths.go",
         "android/prebuilt.go",
         "android/register.go",
+        "android/testing.go",
         "android/util.go",
         "android/variable.go",