unit tests: Shrink unit test partition table so tests can run on 2MB of flash

tools/unit-test-app/partition_table_unit_test_app.csv

@@ -6,7 +6,9 @@ nvs,        data, nvs,     0x9000,  0x4000
 otadata,    data, ota,     0xd000,  0x2000
 phy_init,   data, phy,     0xf000,  0x1000
 factory,    0,    0,       0x10000, 1M
-ota_0,      0,    ota_0,   ,        1M
-ota_1,      0,    ota_1,   ,        1M
+# these OTA partitions are used for tests, but can't fit real OTA apps in them
+# (done this way so tests can run in 2MB of flash.)
+ota_0,      0,    ota_0,   ,        128K
+ota_1,      0,    ota_1,   ,        128K
 # flash_test partition used for SPI flash tests
 flash_test, 0x55, 0x55,  ,        512K