Improve reliability of KVStore general tests

In kvstore_init, prior to initializing the kvstore, erase the
underlying block storage device. This ensures that each test run
starts from a consistent state and avoids failures that can result
if a previous test run left the storage in an inconsistent state.

Author: Kyle Kearney

features/storage/TESTS/kvstore/general_tests_phase_1/main.cpp

@@ -85,6 +85,8 @@ static void kvstore_init()
     res = bd->init();
     TEST_ASSERT_EQUAL_ERROR_CODE(0, res);
     int erase_val = bd->get_erase_value();
+    // Clear out any stale data that might be left from a previous test
+    bd->erase(0, bd->size());
     res = bd->deinit();
     TEST_ASSERT_EQUAL_ERROR_CODE(0, res);
 

features/storage/TESTS/kvstore/general_tests_phase_2/main.cpp

@@ -85,6 +85,8 @@ static void kvstore_init()
     res = bd->init();
     TEST_ASSERT_EQUAL_ERROR_CODE(0, res);
     int erase_val = bd->get_erase_value();
+    // Clear out any stale data that might be left from a previous test
+    bd->erase(0, bd->size());
     res = bd->deinit();
     TEST_ASSERT_EQUAL_ERROR_CODE(0, res);