Fix OOM in UploadBsaUnavailableDomains action

The action was using string concatenation to generate the upload content.
This causes an OOM when string length exceeds 25MB on our current VM.

This PR witches to streaming upload.

Also added an HTTP upload test.

Author: weiminyu

core/build.gradle

@@ -58,6 +58,8 @@ def fragileTestPatterns = [
     // Changes cache timeouts and for some reason appears to have contention
     // with other tests.
     "google/registry/whois/WhoisCommandFactoryTest.*",
+    // Breaks random other tests when running with standardTests.
+    "google/registry/bsa/UploadBsaUnavailableDomainsActionTest.*",
     // Currently changes a global configuration parameter that for some reason
     // results in timestamp inversions for other tests.  TODO(mmuller): fix.
     "google/registry/flows/host/HostInfoFlowTest.*",

core/src/test/java/google/registry/bsa/UploadBsaUnavailableDomainsActionTest.java

@@ -68,7 +68,6 @@
 import org.joda.time.DateTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.condition.DisabledIfEnvironmentVariable;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.api.extension.RegisterExtension;
 import org.mockito.Mock;
@@ -138,8 +137,6 @@ void calculatesEntriesCorrectly() throws Exception {
         .sendNotification("BSA daily upload completed with errors", "Please see logs for details.");
   }
 
-  // TODO(weiminyu): Breaks other tests on Kokoro. Investigate.
-  @DisabledIfEnvironmentVariable(named = "KOKORO_JOB_NAME", matches = ".*")
   @Test
   void uploadToBsaTest() throws Exception {
     TestLogHandler logHandler = new TestLogHandler();