Filter out empty environment variables

LottieSample/src/androidTest/java/com/airbnb/lottie/samples/HappoSnapshotter.kt

diff --git a/LottieSample/src/androidTest/java/com/airbnb/lottie/samples/HappoSnapshotter.kt b/LottieSample/src/androidTest/java/com/airbnb/lottie/samples/HappoSnapshotter.kt
index 781d0d0..fed3160 100644
--- a/LottieSample/src/androidTest/java/com/airbnb/lottie/samples/HappoSnapshotter.kt
+++ b/LottieSample/src/androidTest/java/com/airbnb/lottie/samples/HappoSnapshotter.kt
@@ -61,11 +61,8 @@
     private val happoSecretKey = BC.HappoSecretKey
     private val gitBranch = URLEncoder.encode((if (BC.BITRISE_GIT_BRANCH == "null") BC.GIT_BRANCH else BC.BITRISE_GIT_BRANCH).replace("/", "_"), "UTF-8")
     private val androidVersion = "android${Build.VERSION.SDK_INT}"
-    private val reportNames = listOfNotNull(
-            "${BC.GIT_SHA}-$androidVersion",
-            "$gitBranch-$androidVersion",
-            "${BuildConfig.VERSION_NAME}-$androidVersion"
-    )
+    private val reportNamePrefixes = listOf(BC.GIT_SHA, gitBranch, BuildConfig.VERSION_NAME).filter { it.isNotBlank() }
+    private val reportNames = reportNamePrefixes.map { "$it-$androidVersion" }
 
     private val okhttp = OkHttpClient()