Revert "Adjust error resilience test data rate."

This reverts commit b24735c6
since the adjusted threshold doesn't allow the existing tests
to pass. Will disable the failing test in a separate commit.

Change-Id: I26d41cf6175f300bbad493cecdc96e6b0dd6f2fe

test/error_resilience_test.cc

@@ -182,7 +182,7 @@ TEST_P(ErrorResilienceTest, OnVersusOff) {
 TEST_P(ErrorResilienceTest, DropFramesWithoutRecovery) {
   const vpx_rational timebase = { 33333333, 1000000000 };
   cfg_.g_timebase = timebase;
-  cfg_.rc_target_bitrate = 1500;
+  cfg_.rc_target_bitrate = 500;
 
   init_flags_ = VPX_CODEC_USE_PSNR;