Use IsEnvTrue for USE_BAZEL_ANALYSIS check.

Make this consistent with the check in soong_ui: https://cs.android.com/android/platform/superproject/+/master:build/soong/ui/build/config.go;l=930;drc=0b55bdb7af7ab2a039fefc88086f0ee41c00ac69

Change-Id: I8d57fafa954ce3dd041cc38250819531125d81ac
Test: TH
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index b11b474..c6364af 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -205,7 +205,7 @@
 func NewBazelContext(c *config) (BazelContext, error) {
 	// TODO(cparsons): Assess USE_BAZEL=1 instead once "mixed Soong/Bazel builds"
 	// are production ready.
-	if c.Getenv("USE_BAZEL_ANALYSIS") != "1" {
+	if !c.IsEnvTrue("USE_BAZEL_ANALYSIS") {
 		return noopBazelContext{}, nil
 	}